[PATCHSET 00/18] perf tools: Introduce new 'ftrace' command (5)

[PATCHSET 00/18] perf tools: Introduce new 'ftrace' command (5)

[Namhyung Kim]

Hello,

This patchset implements a front-end tool for kernel's ftrace.  It
uses function_graph tracer by default and normal function tracer is
also supported.  (Of course you need to enable those tracers in your
kernel first.)

This version is almost merely a rebase onto current development, and I
throw it out only for not buried in the piles of patches. :) So
there're something that weren't addressed yet from previous feedback.
But I really want to have an agreement on multi-file support before
going further.

v5 changes:
  * rebase on current acme/perf/core
  * fix bug on record subcommand
  * add basic filter support 

I pushed it out to 'perf/ftrace-v5' branch on my tree at:

  git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git


Any comments are welcome, thanks,
Namhyung


Namhyung Kim (18):
  perf util: Save pid-cmdline mapping into tracing header
  perf util: Add more debug message on failure path
  perf tools: Introduce new 'ftrace' tool
  perf ftrace: Add support for --pid option
  perf ftrace: Add support for -a and -C option
  perf ftrace: Split "live" sub-command
  perf ftrace: Add 'record' sub-command
  perf ftrace: Add 'show' sub-command
  perf ftrace: Add 'report' sub-command
  perf ftrace: Add dump_printf() for low-level debugging
  perf ftrace: Use pager for displaying result
  perf ftrace: Cleanup using ftrace_setup/teardown()
  perf tools: Add document for perf-ftrace command
  perf ftrace: Add a signal handler for SIGSEGV
  perf ftrace: Add --clock option
  perf ftrace: Show leaf-functions as oneliner
  perf ftrace: Tidy up the function graph output of 'show' subcommand
  perf ftrace: Add --filter option

 tools/perf/Documentation/perf-ftrace.txt |  122 ++
 tools/perf/Makefile.perf                 |    1 +
 tools/perf/builtin-ftrace.c              | 1861 ++++++++++++++++++++++++++++++
 tools/perf/builtin.h                     |    1 +
 tools/perf/command-list.txt              |    1 +
 tools/perf/perf.c                        |    1 +
 tools/perf/util/cpumap.c                 |   45 +
 tools/perf/util/cpumap.h                 |    1 +
 tools/perf/util/debug.c                  |    8 +-
 tools/perf/util/debug.h                  |    2 +-
 tools/perf/util/header.c                 |    4 +-
 tools/perf/util/session.c                |    2 +-
 tools/perf/util/trace-event-info.c       |   33 +-
 tools/perf/util/trace-event-parse.c      |   17 +
 tools/perf/util/trace-event-read.c       |   77 +-
 tools/perf/util/trace-event.h            |    1 +
 16 files changed, 2156 insertions(+), 21 deletions(-)
 create mode 100644 tools/perf/Documentation/perf-ftrace.txt
 create mode 100644 tools/perf/builtin-ftrace.c


Following is the original description and example.
-----
It consists of 4 subcommands: live, record, show and report.

'perf ftrace live' just triggers ftrace and relay kernel buffer
contents to stdout.  It does no processing in the tool side.

'perf ftrace record' starts ftrace and saves its result to per-cpu
files and a perf.header file in the perf.data.dir directory.
Recording was done by multiple threads (a thread per cpu) in order not
to miss events overrun.  The perf.header file is compatible to current
perf.data file and contains useful information and sample data.

The sample data were synthesized for each recorded cpu to provide more
information - I'm not sure it's really needed though.

Once you had run 'perf ftrace record', you could play with other
subcommands.

'perf ftrace show' displays function traces like 'live' subcommand or
trace-cmd does.  It's not useful than them at this time but it could
be improved soon.

'perf ftrace report' displays usual 'perf report' style output from
the function trace data.  You can see which function is called most
frequently for example.  Currently it uses 1 as a period value for
each entry but we might use funcgraph_exit->calltime to get proper
overhead later.

Example below:

  # perf ftrace record sleep 0.1
  # ls -l perf.data.dir
  total 5568
  -rw-r--r--. 1 root root 3514375 Apr 23 16:43 perf.header
  -rw-r--r--. 1 root root   90112 Apr 23 16:43 trace-cpu0.buf
  -rw-r--r--. 1 root root       0 Apr 23 16:43 trace-cpu1.buf
  -rw-r--r--. 1 root root 2093056 Apr 23 16:43 trace-cpu2.buf
  -rw-r--r--. 1 root root       0 Apr 23 16:43 trace-cpu3.buf

  # perf ftrace show
  overriding event (11) ftrace:funcgraph_entry with new print handler
  overriding event (10) ftrace:funcgraph_exit with new print handler
    0)   0.065 us |  __fsnotify_parent();
    0)            |  fsnotify() {
    0)   0.060 us |    __srcu_read_lock();
    0)   0.040 us |    __srcu_read_unlock();
    0)   0.652 us |  }
    0)   0.040 us |  fput();
    0)            |  __audit_syscall_exit() {
    0)            |    path_put() {
    0)   0.037 us |      dput();
    0)   0.032 us |      mntput();
    0)   0.563 us |    }
    0)   0.035 us |    unroll_tree_refs();
    0)   0.035 us |    kfree();
    0)   1.284 us |  }
    0)            |  __audit_syscall_entry() {
    0)   0.029 us |    current_kernel_time();
    0)   0.239 us |  }
    0)            |  sys_write() {
    0)   0.155 us |    fget_light();
    0)            |    vfs_write() {
    0)            |      rw_verify_area() {
    0)            |        security_file_permission() {
    0)            |          selinux_file_permission() {
    0)            |            file_has_perm() {
    0)            |              inode_has_perm.isra.31.constprop.61() {
    0)   0.181 us |                avc_has_perm_flags();
    0)   0.405 us |              }
    0)   0.629 us |            }
    0)   1.024 us |          }
    0)   1.247 us |        }
    0)   1.596 us |      }
    0)            |      do_sync_write() {

  # perf ftrace report
  # ========
  # captured on: Tue Jul 30 18:02:34 2013
  # hostname : sejong.aot.lge.com
  # os release : 3.9.10-100.fc17.x86_64
  # perf version : 3.11.rc1.gcdd406
  # arch : x86_64
  # nrcpus online : 12
  # nrcpus avail : 12
  # cpudesc : Intel(R) Core(TM) i7-3930K CPU @ 3.20GHz
  # cpuid : GenuineIntel,6,45,7
  # total memory : 32901840 kB
  # cmdline : /home/namhyung/project/linux/tools/perf/perf ftrace record sleep 0.1 
  # event : name = ftrace:funcgraph_entry, type = 2, config = 0xb, config1 = 0x0,
  # event : name = ftrace:funcgraph_exit, type = 2, config = 0xa, config1 = 0x0,
  # HEADER_CPU_TOPOLOGY info available, use -I to display
  # HEADER_NUMA_TOPOLOGY info available, use -I to display
  # ========
  #
  # Samples: 22K of event 'ftrace:funcgraph_entry'
  # Event count (approx.): 22433
  #
  # Overhead  Command      Shared Object                          Symbol
  # ........  .......  .................  ..............................
  #
       7.90%    sleep  [kernel.kallsyms]  [k] _cond_resched             
       4.57%    sleep  [kernel.kallsyms]  [k] ebitmap_get_bit           
       3.50%    sleep  [kernel.kallsyms]  [k] __phys_addr               
       3.12%    sleep  [kernel.kallsyms]  [k] _raw_spin_lock            
       3.09%    sleep  [kernel.kallsyms]  [k] kmem_cache_free           
       2.93%    sleep  [kernel.kallsyms]  [k] __slab_free               
       2.86%    sleep  [kernel.kallsyms]  [k] __tlb_remove_page         
       2.35%    sleep  [kernel.kallsyms]  [k] vm_normal_page            
       2.33%    sleep  [kernel.kallsyms]  [k] page_remove_rmap          
       1.87%    sleep  [kernel.kallsyms]  [k] mutex_unlock               

-- 
1.7.11.7

[PATCH 01/18] perf util: Save pid-cmdline mapping into tracing header

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

Current trace info data lacks the saved cmdline mapping which is
needed for pevent to find out the comm of a task.  Add this and bump
up the version number so that perf can determine its presence when
reading.

This is mostly corresponding to trace.dat file version 6, but still
lacks 4 byte of number of cpus, and 10 bytes of type string - and I
think we don't need those anyway.

Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/util/trace-event-info.c  | 33 ++++++++++++++++++++++++++++++++-
 tools/perf/util/trace-event-parse.c | 17 +++++++++++++++++
 tools/perf/util/trace-event-read.c  | 36 ++++++++++++++++++++++++++++++++++--
 tools/perf/util/trace-event.h       |  1 +
 4 files changed, 84 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/trace-event-info.c b/tools/perf/util/trace-event-info.c
index f3c9e551bd35..48678ca4c4d6 100644
--- a/tools/perf/util/trace-event-info.c
+++ b/tools/perf/util/trace-event-info.c
@@ -41,7 +41,7 @@
 #include <lk/debugfs.h>
 #include "evsel.h"
 
-#define VERSION "0.5"
+#define VERSION "0.6"
 
 static int output_fd;
 
@@ -390,6 +390,34 @@ out:
 	return err;
 }
 
+static int record_saved_cmdline(void)
+{
+	unsigned int size;
+	char *path;
+	struct stat st;
+	int ret, err = 0;
+
+	path = get_tracing_file("saved_cmdlines");
+	if (!path) {
+		pr_debug("can't get tracing/saved_cmdline");
+		return -ENOMEM;
+	}
+
+	ret = stat(path, &st);
+	if (ret < 0) {
+		/* not found */
+		size = 0;
+		if (write(output_fd, &size, 8) != 8)
+			err = -EIO;
+		goto out;
+	}
+	err = record_file(path, 8);
+
+out:
+	put_tracing_file(path);
+	return err;
+}
+
 static void
 put_tracepoints_path(struct tracepoint_path *tps)
 {
@@ -550,6 +578,9 @@ struct tracing_data *tracing_data_get(struct list_head *pattrs,
 	if (err)
 		goto out;
 	err = record_ftrace_printk();
+	if (err)
+		goto out;
+	err = record_saved_cmdline();
 
 out:
 	/*
diff --git a/tools/perf/util/trace-event-parse.c b/tools/perf/util/trace-event-parse.c
index 6681f71f2f95..94912b7b5027 100644
--- a/tools/perf/util/trace-event-parse.c
+++ b/tools/perf/util/trace-event-parse.c
@@ -196,6 +196,23 @@ void parse_ftrace_printk(struct pevent *pevent,
 	}
 }
 
+void parse_saved_cmdline(struct pevent *pevent,
+			 char *file, unsigned int size __maybe_unused)
+{
+	char *comm;
+	char *line;
+	char *next = NULL;
+	int pid;
+
+	line = strtok_r(file, "\n", &next);
+	while (line) {
+		sscanf(line, "%d %ms", &pid, &comm);
+		pevent_register_comm(pevent, comm, pid);
+		free(comm);
+		line = strtok_r(NULL, "\n", &next);
+	}
+}
+
 int parse_ftrace_file(struct pevent *pevent, char *buf, unsigned long size)
 {
 	return pevent_parse_event(pevent, buf, size, "ftrace");
diff --git a/tools/perf/util/trace-event-read.c b/tools/perf/util/trace-event-read.c
index f2112270c663..e084e5e654b6 100644
--- a/tools/perf/util/trace-event-read.c
+++ b/tools/perf/util/trace-event-read.c
@@ -343,6 +343,31 @@ static int read_event_files(struct pevent *pevent)
 	return 0;
 }
 
+static int read_saved_cmdline(struct pevent *pevent)
+{
+	unsigned long long size;
+	char *buf;
+
+	/* it can have 0 size */
+	size = read8(pevent);
+	if (!size)
+		return 0;
+
+	buf = malloc(size + 1);
+	if (buf == NULL)
+		return -1;
+
+	if (do_read(buf, size) < 0) {
+		free(buf);
+		return -1;
+	}
+
+	parse_saved_cmdline(pevent, buf, size);
+
+	free(buf);
+	return 0;
+}
+
 ssize_t trace_report(int fd, struct pevent **ppevent, bool __repipe)
 {
 	char buf[BUFSIZ];
@@ -383,10 +408,11 @@ ssize_t trace_report(int fd, struct pevent **ppevent, bool __repipe)
 		return -1;
 	if (show_version)
 		printf("version = %s\n", version);
-	free(version);
 
-	if (do_read(buf, 1) < 0)
+	if (do_read(buf, 1) < 0) {
+		free(version);
 		return -1;
+	}
 	file_bigendian = buf[0];
 	host_bigendian = bigendian();
 
@@ -422,6 +448,11 @@ ssize_t trace_report(int fd, struct pevent **ppevent, bool __repipe)
 	err = read_ftrace_printk(pevent);
 	if (err)
 		goto out;
+	if (!strcmp(version, "0.6")) {
+		err = read_saved_cmdline(pevent);
+		if (err)
+			goto out;
+	}
 
 	size = trace_data_size;
 	repipe = false;
@@ -438,5 +469,6 @@ ssize_t trace_report(int fd, struct pevent **ppevent, bool __repipe)
 out:
 	if (pevent)
 		pevent_free(pevent);
+	free(version);
 	return size;
 }
diff --git a/tools/perf/util/trace-event.h b/tools/perf/util/trace-event.h
index 04df63114109..73567d0a27c2 100644
--- a/tools/perf/util/trace-event.h
+++ b/tools/perf/util/trace-event.h
@@ -26,6 +26,7 @@ raw_field_value(struct event_format *event, const char *name, void *data);
 
 void parse_proc_kallsyms(struct pevent *pevent, char *file, unsigned int size);
 void parse_ftrace_printk(struct pevent *pevent, char *file, unsigned int size);
+void parse_saved_cmdline(struct pevent *pevent, char *file, unsigned int size);
 
 ssize_t trace_report(int fd, struct pevent **pevent, bool repipe);
 
-- 
1.7.11.7

[PATCH 02/18] perf util: Add more debug message on failure path

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

It's helpful for debugging on tracing features.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/util/header.c           |  4 ++-
 tools/perf/util/trace-event-read.c | 53 ++++++++++++++++++++++++++------------
 2 files changed, 39 insertions(+), 18 deletions(-)

diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index c3e5a3b817ab..f8afefbe99ae 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -2721,8 +2721,10 @@ static int perf_evsel__prepare_tracepoint_event(struct perf_evsel *evsel,
 	}
 
 	event = pevent_find_event(pevent, evsel->attr.config);
-	if (event == NULL)
+	if (event == NULL) {
+		pr_debug("cannot find event format for %d\n", (int)evsel->attr.config);
 		return -1;
+	}
 
 	if (!evsel->name) {
 		snprintf(bf, sizeof(bf), "%s:%s", event->system, event->name);
diff --git a/tools/perf/util/trace-event-read.c b/tools/perf/util/trace-event-read.c
index e084e5e654b6..0e3b3f527320 100644
--- a/tools/perf/util/trace-event-read.c
+++ b/tools/perf/util/trace-event-read.c
@@ -262,39 +262,53 @@ static int read_header_files(struct pevent *pevent)
 
 static int read_ftrace_file(struct pevent *pevent, unsigned long long size)
 {
+	int ret;
 	char *buf;
 
 	buf = malloc(size);
-	if (buf == NULL)
+	if (buf == NULL) {
+		pr_debug("memory allocation failure\n");
 		return -1;
+	}
 
-	if (do_read(buf, size) < 0) {
-		free(buf);
-		return -1;
+	ret = do_read(buf, size);
+	if (ret < 0) {
+		pr_debug("error reading ftrace file.\n");
+		goto out;
 	}
 
-	parse_ftrace_file(pevent, buf, size);
+	ret = parse_ftrace_file(pevent, buf, size);
+	if (ret < 0)
+		pr_debug("error parsing ftrace file.\n");
+out:
 	free(buf);
-	return 0;
+	return ret;
 }
 
 static int read_event_file(struct pevent *pevent, char *sys,
 			    unsigned long long size)
 {
+	int ret;
 	char *buf;
 
 	buf = malloc(size);
-	if (buf == NULL)
+	if (buf == NULL) {
+		pr_debug("memory allocation failure\n");
 		return -1;
+	}
 
-	if (do_read(buf, size) < 0) {
+	ret = do_read(buf, size);
+	if (ret < 0) {
 		free(buf);
-		return -1;
+		goto out;
 	}
 
-	parse_event_file(pevent, buf, size, sys);
+	ret = parse_event_file(pevent, buf, size, sys);
+	if (ret < 0)
+		pr_debug("error parsing event file.\n");
+out:
 	free(buf);
-	return 0;
+	return ret;
 }
 
 static int read_ftrace_files(struct pevent *pevent)
@@ -347,6 +361,7 @@ static int read_saved_cmdline(struct pevent *pevent)
 {
 	unsigned long long size;
 	char *buf;
+	int ret;
 
 	/* it can have 0 size */
 	size = read8(pevent);
@@ -354,18 +369,22 @@ static int read_saved_cmdline(struct pevent *pevent)
 		return 0;
 
 	buf = malloc(size + 1);
-	if (buf == NULL)
+	if (buf == NULL) {
+		pr_debug("memory allocation failure\n");
 		return -1;
+	}
 
-	if (do_read(buf, size) < 0) {
-		free(buf);
-		return -1;
+	ret = do_read(buf, size);
+	if (ret < 0) {
+		pr_debug("error reading saved cmdlines\n");
+		goto out;
 	}
 
 	parse_saved_cmdline(pevent, buf, size);
-
+	ret = 0;
+out:
 	free(buf);
-	return 0;
+	return ret;
 }
 
 ssize_t trace_report(int fd, struct pevent **ppevent, bool __repipe)
-- 
1.7.11.7

[PATCH 03/18] perf tools: Introduce new 'ftrace' tool

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

The ftrace command is a simple wrapper of kernel's ftrace
functionality.  It only supports single thread tracing currently and
just reads trace_pipe in text and then write it to stdout.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/Makefile.perf    |   1 +
 tools/perf/builtin-ftrace.c | 228 ++++++++++++++++++++++++++++++++++++++++++++
 tools/perf/builtin.h        |   1 +
 tools/perf/command-list.txt |   1 +
 tools/perf/perf.c           |   1 +
 5 files changed, 232 insertions(+)
 create mode 100644 tools/perf/builtin-ftrace.c

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index c873e039aafb..79058b6a8435 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -431,6 +431,7 @@ BUILTIN_OBJS += $(OUTPUT)builtin-kmem.o
 BUILTIN_OBJS += $(OUTPUT)builtin-lock.o
 BUILTIN_OBJS += $(OUTPUT)builtin-kvm.o
 BUILTIN_OBJS += $(OUTPUT)builtin-inject.o
+BUILTIN_OBJS += $(OUTPUT)builtin-ftrace.o
 BUILTIN_OBJS += $(OUTPUT)tests/builtin-test.o
 BUILTIN_OBJS += $(OUTPUT)builtin-mem.o
 
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
new file mode 100644
index 000000000000..6f3dd02c5b9a
--- /dev/null
+++ b/tools/perf/builtin-ftrace.c
@@ -0,0 +1,228 @@
+/*
+ * builtin-ftrace.c
+ *
+ * Copyright (c) 2013  LG Electronics,  Namhyung Kim <namhyung@kernel.org>
+ *
+ * Released under the GPL v2.
+ */
+
+#include "builtin.h"
+#include "perf.h"
+
+#include <unistd.h>
+#include <signal.h>
+
+#include "util/debug.h"
+#include "util/parse-options.h"
+#include "util/evlist.h"
+#include "util/target.h"
+#include "util/thread_map.h"
+
+
+#define DEFAULT_TRACER  "function_graph"
+
+struct perf_ftrace {
+	struct perf_evlist *evlist;
+	struct perf_target target;
+	const char *tracer;
+};
+
+static bool done;
+
+static void sig_handler(int sig __maybe_unused)
+{
+	done = true;
+}
+
+static int write_tracing_file(const char *name, const char *val)
+{
+	char *file;
+	int fd, ret = -1;
+	ssize_t size = strlen(val);
+
+	file = get_tracing_file(name);
+	if (!file) {
+		pr_debug("cannot get tracing file: %s\n", name);
+		return -1;
+	}
+
+	fd = open(file, O_WRONLY);
+	if (fd < 0) {
+		pr_debug("cannot open tracing file: %s\n", name);
+		goto out;
+	}
+
+	if (write(fd, val, size) == size)
+		ret = 0;
+	else
+		pr_debug("write '%s' to tracing/%s failed\n", val, name);
+
+	close(fd);
+out:
+	put_tracing_file(file);
+	return ret;
+}
+
+static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
+{
+	if (write_tracing_file("tracing_on", "0") < 0)
+		return -1;
+
+	if (write_tracing_file("current_tracer", "nop") < 0)
+		return -1;
+
+	if (write_tracing_file("set_ftrace_pid", " ") < 0)
+		return -1;
+
+	return 0;
+}
+
+static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
+{
+	char *trace_file;
+	int trace_fd;
+	char *trace_pid;
+	char buf[4096];
+	struct pollfd pollfd = {
+		.events = POLLIN,
+	};
+
+	if (geteuid() != 0) {
+		pr_err("ftrace only works for root!\n");
+		return -1;
+	}
+
+	if (argc < 1)
+		return -1;
+
+	signal(SIGINT, sig_handler);
+	signal(SIGUSR1, sig_handler);
+	signal(SIGCHLD, sig_handler);
+
+	reset_tracing_files(ftrace);
+
+	/* reset ftrace buffer */
+	if (write_tracing_file("trace", "0") < 0)
+		goto out;
+
+	if (perf_evlist__prepare_workload(ftrace->evlist, &ftrace->target,
+					  argv, false, true) < 0)
+		goto out;
+
+	if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
+		pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
+		goto out;
+	}
+
+	if (asprintf(&trace_pid, "%d", ftrace->evlist->threads->map[0]) < 0) {
+		pr_err("failed to allocate pid string\n");
+		goto out;
+	}
+
+	if (write_tracing_file("set_ftrace_pid", trace_pid) < 0) {
+		pr_err("failed to set pid: %s\n", trace_pid);
+		goto out_free_pid;
+	}
+
+	trace_file = get_tracing_file("trace_pipe");
+	if (!trace_file) {
+		pr_err("failed to open trace_pipe\n");
+		goto out_free_pid;
+	}
+
+	trace_fd = open(trace_file, O_RDONLY);
+
+	put_tracing_file(trace_file);
+
+	if (trace_fd < 0) {
+		pr_err("failed to open trace_pipe\n");
+		goto out_free_pid;
+	}
+
+	fcntl(trace_fd, F_SETFL, O_NONBLOCK);
+	pollfd.fd = trace_fd;
+
+	if (write_tracing_file("tracing_on", "1") < 0) {
+		pr_err("can't enable tracing\n");
+		goto out_close_fd;
+	}
+
+	perf_evlist__start_workload(ftrace->evlist);
+
+	while (!done) {
+		if (poll(&pollfd, 1, -1) < 0)
+			break;
+
+		if (pollfd.revents & POLLIN) {
+			int n = read(trace_fd, buf, sizeof(buf));
+			if (n < 0)
+				break;
+			if (fwrite(buf, n, 1, stdout) != 1)
+				break;
+		}
+	}
+
+	write_tracing_file("tracing_on", "0");
+
+	/* read remaining buffer contents */
+	while (true) {
+		int n = read(trace_fd, buf, sizeof(buf));
+		if (n <= 0)
+			break;
+		if (fwrite(buf, n, 1, stdout) != 1)
+			break;
+	}
+
+out_close_fd:
+	close(trace_fd);
+out_free_pid:
+	free(trace_pid);
+out:
+	reset_tracing_files(ftrace);
+
+	return done ? 0 : -1;
+}
+
+int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused)
+{
+	int ret;
+	struct perf_ftrace ftrace = {
+		.target = { .uid = UINT_MAX, },
+	};
+	const char * const ftrace_usage[] = {
+		"perf ftrace [<options>] [<command>]",
+		"perf ftrace [<options>] -- <command> [<options>]",
+		NULL
+	};
+	const struct option ftrace_options[] = {
+	OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
+		   "tracer to use: function_graph or function"),
+	OPT_INCR('v', "verbose", &verbose,
+		 "be more verbose"),
+	OPT_END()
+	};
+
+	argc = parse_options(argc, argv, ftrace_options, ftrace_usage,
+			    PARSE_OPT_STOP_AT_NON_OPTION);
+	if (!argc)
+		usage_with_options(ftrace_usage, ftrace_options);
+
+	ftrace.evlist = perf_evlist__new();
+	if (ftrace.evlist == NULL)
+		return -ENOMEM;
+
+	ret = perf_evlist__create_maps(ftrace.evlist, &ftrace.target);
+	if (ret < 0)
+		goto out_delete_evlist;
+
+	if (ftrace.tracer == NULL)
+		ftrace.tracer = DEFAULT_TRACER;
+
+	ret = __cmd_ftrace(&ftrace, argc, argv);
+
+	perf_evlist__delete_maps(ftrace.evlist);
+out_delete_evlist:
+	perf_evlist__delete(ftrace.evlist);
+
+	return ret;
+}
diff --git a/tools/perf/builtin.h b/tools/perf/builtin.h
index b210d62907e4..55da75c4e990 100644
--- a/tools/perf/builtin.h
+++ b/tools/perf/builtin.h
@@ -37,6 +37,7 @@ extern int cmd_test(int argc, const char **argv, const char *prefix);
 extern int cmd_trace(int argc, const char **argv, const char *prefix);
 extern int cmd_inject(int argc, const char **argv, const char *prefix);
 extern int cmd_mem(int argc, const char **argv, const char *prefix);
+extern int cmd_ftrace(int argc, const char **argv, const char *prefix);
 
 extern int find_scripts(char **scripts_array, char **scripts_path_array);
 #endif
diff --git a/tools/perf/command-list.txt b/tools/perf/command-list.txt
index 0906fc401c52..c24d76e61bc1 100644
--- a/tools/perf/command-list.txt
+++ b/tools/perf/command-list.txt
@@ -9,6 +9,7 @@ perf-buildid-cache		mainporcelain common
 perf-buildid-list		mainporcelain common
 perf-diff			mainporcelain common
 perf-evlist			mainporcelain common
+perf-ftrace			mainporcelain common
 perf-inject			mainporcelain common
 perf-kmem			mainporcelain common
 perf-kvm			mainporcelain common
diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 8b38b4e80ec2..2009d2d0e0b8 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -61,6 +61,7 @@ static struct cmd_struct commands[] = {
 #endif
 	{ "inject",	cmd_inject,	0 },
 	{ "mem",	cmd_mem,	0 },
+	{ "ftrace",	cmd_ftrace,	0 },
 };
 
 struct pager_config {
-- 
1.7.11.7

[PATCH 04/18] perf ftrace: Add support for --pid option

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

The -p (--pid) option enables to trace existing process by its pid.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-ftrace.c | 89 ++++++++++++++++++++++++++++++++-------------
 1 file changed, 63 insertions(+), 26 deletions(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 6f3dd02c5b9a..bd415f2b1cde 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -11,6 +11,7 @@
 
 #include <unistd.h>
 #include <signal.h>
+#include <fcntl.h>
 
 #include "util/debug.h"
 #include "util/parse-options.h"
@@ -34,11 +35,12 @@ static void sig_handler(int sig __maybe_unused)
 	done = true;
 }
 
-static int write_tracing_file(const char *name, const char *val)
+static int __write_tracing_file(const char *name, const char *val, bool append)
 {
 	char *file;
 	int fd, ret = -1;
 	ssize_t size = strlen(val);
+	int flags = O_WRONLY;
 
 	file = get_tracing_file(name);
 	if (!file) {
@@ -46,7 +48,12 @@ static int write_tracing_file(const char *name, const char *val)
 		return -1;
 	}
 
-	fd = open(file, O_WRONLY);
+	if (append)
+		flags |= O_APPEND;
+	else
+		flags |= O_TRUNC;
+
+	fd = open(file, flags);
 	if (fd < 0) {
 		pr_debug("cannot open tracing file: %s\n", name);
 		goto out;
@@ -63,6 +70,16 @@ out:
 	return ret;
 }
 
+static int write_tracing_file(const char *name, const char *val)
+{
+	return __write_tracing_file(name, val, false);
+}
+
+static int append_tracing_file(const char *name, const char *val)
+{
+	return __write_tracing_file(name, val, true);
+}
+
 static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
 {
 	if (write_tracing_file("tracing_on", "0") < 0)
@@ -77,11 +94,27 @@ static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
 	return 0;
 }
 
+static int set_tracing_pid(struct perf_ftrace *ftrace)
+{
+	int i;
+	char buf[16];
+
+	if (perf_target__has_cpu(&ftrace->target))
+		return 0;
+
+	for (i = 0; i < thread_map__nr(ftrace->evlist->threads); i++) {
+		scnprintf(buf, sizeof(buf), "%d",
+			  ftrace->evlist->threads->map[i]);
+		if (append_tracing_file("set_ftrace_pid", buf) < 0)
+			return -1;
+	}
+	return 0;
+}
+
 static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 {
 	char *trace_file;
 	int trace_fd;
-	char *trace_pid;
 	char buf[4096];
 	struct pollfd pollfd = {
 		.events = POLLIN,
@@ -92,42 +125,37 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 		return -1;
 	}
 
-	if (argc < 1)
-		return -1;
-
 	signal(SIGINT, sig_handler);
 	signal(SIGUSR1, sig_handler);
 	signal(SIGCHLD, sig_handler);
 
-	reset_tracing_files(ftrace);
+	if (reset_tracing_files(ftrace) < 0)
+		goto out;
 
 	/* reset ftrace buffer */
 	if (write_tracing_file("trace", "0") < 0)
 		goto out;
 
-	if (perf_evlist__prepare_workload(ftrace->evlist, &ftrace->target,
-					  argv, false, true) < 0)
-		goto out;
-
-	if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
-		pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
+	if (argc && perf_evlist__prepare_workload(ftrace->evlist,
+						  &ftrace->target,
+						  argv, false, true) < 0) {
 		goto out;
 	}
 
-	if (asprintf(&trace_pid, "%d", ftrace->evlist->threads->map[0]) < 0) {
-		pr_err("failed to allocate pid string\n");
-		goto out;
+	if (set_tracing_pid(ftrace) < 0) {
+		pr_err("failed to set ftrace pid\n");
+		goto out_reset;
 	}
 
-	if (write_tracing_file("set_ftrace_pid", trace_pid) < 0) {
-		pr_err("failed to set pid: %s\n", trace_pid);
-		goto out_free_pid;
+	if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
+		pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
+		goto out_reset;
 	}
 
 	trace_file = get_tracing_file("trace_pipe");
 	if (!trace_file) {
 		pr_err("failed to open trace_pipe\n");
-		goto out_free_pid;
+		goto out_reset;
 	}
 
 	trace_fd = open(trace_file, O_RDONLY);
@@ -136,7 +164,7 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 
 	if (trace_fd < 0) {
 		pr_err("failed to open trace_pipe\n");
-		goto out_free_pid;
+		goto out_reset;
 	}
 
 	fcntl(trace_fd, F_SETFL, O_NONBLOCK);
@@ -175,11 +203,9 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 
 out_close_fd:
 	close(trace_fd);
-out_free_pid:
-	free(trace_pid);
-out:
+out_reset:
 	reset_tracing_files(ftrace);
-
+out:
 	return done ? 0 : -1;
 }
 
@@ -197,6 +223,8 @@ int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused)
 	const struct option ftrace_options[] = {
 	OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
 		   "tracer to use: function_graph or function"),
+	OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
+		   "trace on existing process id"),
 	OPT_INCR('v', "verbose", &verbose,
 		 "be more verbose"),
 	OPT_END()
@@ -204,9 +232,18 @@ int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused)
 
 	argc = parse_options(argc, argv, ftrace_options, ftrace_usage,
 			    PARSE_OPT_STOP_AT_NON_OPTION);
-	if (!argc)
+	if (!argc && perf_target__none(&ftrace.target))
 		usage_with_options(ftrace_usage, ftrace_options);
 
+	ret = perf_target__validate(&ftrace.target);
+	if (ret) {
+		char errbuf[512];
+
+		perf_target__strerror(&ftrace.target, ret, errbuf, 512);
+		pr_err("%s\n", errbuf);
+		return -EINVAL;
+	}
+
 	ftrace.evlist = perf_evlist__new();
 	if (ftrace.evlist == NULL)
 		return -ENOMEM;
-- 
1.7.11.7

[PATCH 05/18] perf ftrace: Add support for -a and -C option

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

The -a/--all-cpus and -C/--cpu option is for controlling tracing cpus.
To do that, add and use cpu_map__sprintf() function.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-ftrace.c | 69 +++++++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/cpumap.c    | 45 +++++++++++++++++++++++++++++
 tools/perf/util/cpumap.h    |  1 +
 3 files changed, 115 insertions(+)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index bd415f2b1cde..642aa49c66d7 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -18,6 +18,7 @@
 #include "util/evlist.h"
 #include "util/target.h"
 #include "util/thread_map.h"
+#include "util/cpumap.h"
 
 
 #define DEFAULT_TRACER  "function_graph"
@@ -80,6 +81,8 @@ static int append_tracing_file(const char *name, const char *val)
 	return __write_tracing_file(name, val, true);
 }
 
+static int reset_tracing_cpu(void);
+
 static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
 {
 	if (write_tracing_file("tracing_on", "0") < 0)
@@ -91,6 +94,9 @@ static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
 	if (write_tracing_file("set_ftrace_pid", " ") < 0)
 		return -1;
 
+	if (reset_tracing_cpu() < 0)
+		return -1;
+
 	return 0;
 }
 
@@ -111,6 +117,60 @@ static int set_tracing_pid(struct perf_ftrace *ftrace)
 	return 0;
 }
 
+static int set_tracing_cpu(struct perf_ftrace *ftrace)
+{
+	char *cpumask;
+	size_t mask_size;
+	int ret;
+	int last_cpu;
+	struct cpu_map *cpumap = ftrace->evlist->cpus;
+
+	if (!perf_target__has_cpu(&ftrace->target))
+		return 0;
+
+	last_cpu = cpumap->map[cpumap->nr - 1];
+	mask_size = (last_cpu + 3) / 4 + 1;
+	mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */
+
+	cpumask = malloc(mask_size);
+	if (cpumask == NULL) {
+		pr_debug("failed to allocate cpu mask\n");
+		return -1;
+	}
+
+	cpu_map__sprintf(cpumap, cpumask);
+
+	ret = write_tracing_file("tracing_cpumask", cpumask);
+
+	free(cpumask);
+	return ret;
+}
+
+static int reset_tracing_cpu(void)
+{
+	char *cpumask;
+	size_t mask_size;
+	int last_cpu;
+	struct cpu_map *cpumap = cpu_map__new(NULL);
+
+	last_cpu = cpumap->map[cpumap->nr - 1];
+	mask_size = (last_cpu + 3) / 4 + 1;
+	mask_size += last_cpu / 32; /* ',' is needed for every 32th cpus */
+
+	cpumask = malloc(mask_size);
+	if (cpumask == NULL) {
+		pr_debug("failed to allocate cpu mask\n");
+		return -1;
+	}
+
+	cpu_map__sprintf(cpumap, cpumask);
+
+	write_tracing_file("tracing_cpumask", cpumask);
+
+	free(cpumask);
+	return 0;
+}
+
 static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 {
 	char *trace_file;
@@ -147,6 +207,11 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 		goto out_reset;
 	}
 
+	if (set_tracing_cpu(ftrace) < 0) {
+		pr_err("failed to set tracing cpumask\n");
+		goto out_reset;
+	}
+
 	if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
 		pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
 		goto out_reset;
@@ -227,6 +292,10 @@ int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused)
 		   "trace on existing process id"),
 	OPT_INCR('v', "verbose", &verbose,
 		 "be more verbose"),
+	OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
+		    "system-wide collection from all CPUs"),
+	OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
+		    "list of cpus to monitor"),
 	OPT_END()
 	};
 
diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c
index beb8cf9f9976..7933839915ea 100644
--- a/tools/perf/util/cpumap.c
+++ b/tools/perf/util/cpumap.c
@@ -187,6 +187,51 @@ size_t cpu_map__fprintf(struct cpu_map *map, FILE *fp)
 	return printed + fprintf(fp, "\n");
 }
 
+static char hex_char(char val)
+{
+	if (0 <= val && val <= 9)
+		return val + '0';
+	if (10 <= val && val < 16)
+		return val - 10 + 'a';
+	return '?';
+}
+
+size_t cpu_map__sprintf(struct cpu_map *map, char *buf)
+{
+	int i, cpu;
+	char *ptr = buf;
+	unsigned char *bitmap;
+	int last_cpu = map->map[map->nr - 1];
+
+	bitmap = zalloc((last_cpu + 7) / 8);
+	if (bitmap == NULL) {
+		buf[0] = '\0';
+		return 0;
+	}
+
+	for (i = 0; i < map->nr; i++) {
+		cpu = map->map[i];
+		bitmap[cpu / 8] |= 1 << (cpu % 8);
+	}
+
+	for (cpu = last_cpu / 4 * 4; cpu >= 0; cpu -= 4) {
+		unsigned char bits = bitmap[cpu / 8];
+
+		if (cpu % 8)
+			bits >>= 4;
+		else
+			bits &= 0xf;
+
+		*ptr++ = hex_char(bits);
+		if ((cpu % 32) == 0 && cpu > 0)
+			*ptr++ = ',';
+	}
+	*ptr++ = '\0';
+
+	free(bitmap);
+	return ptr - buf;
+}
+
 struct cpu_map *cpu_map__dummy_new(void)
 {
 	struct cpu_map *cpus = malloc(sizeof(*cpus) + sizeof(int));
diff --git a/tools/perf/util/cpumap.h b/tools/perf/util/cpumap.h
index b123bb9d6f55..a9a7f19f89d7 100644
--- a/tools/perf/util/cpumap.h
+++ b/tools/perf/util/cpumap.h
@@ -14,6 +14,7 @@ struct cpu_map *cpu_map__dummy_new(void);
 void cpu_map__delete(struct cpu_map *map);
 struct cpu_map *cpu_map__read(FILE *file);
 size_t cpu_map__fprintf(struct cpu_map *map, FILE *fp);
+size_t cpu_map__sprintf(struct cpu_map *map, char *buf);
 int cpu_map__get_socket(struct cpu_map *map, int idx);
 int cpu_map__get_core(struct cpu_map *map, int idx);
 int cpu_map__build_socket_map(struct cpu_map *cpus, struct cpu_map **sockp);
-- 
1.7.11.7

[PATCH 06/18] perf ftrace: Split "live" sub-command

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

Separate out the default behavior to "live" subcommand.  It's a
preparation to support more subcommands like "record" and "report".

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-ftrace.c | 133 ++++++++++++++++++++++++++------------------
 1 file changed, 80 insertions(+), 53 deletions(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 642aa49c66d7..1bb6d1ff0eb1 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -171,19 +171,13 @@ static int reset_tracing_cpu(void)
 	return 0;
 }
 
-static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
+static int do_ftrace_live(struct perf_ftrace *ftrace)
 {
 	char *trace_file;
 	int trace_fd;
 	char buf[4096];
-	struct pollfd pollfd = {
-		.events = POLLIN,
-	};
-
-	if (geteuid() != 0) {
-		pr_err("ftrace only works for root!\n");
-		return -1;
-	}
+	/* sleep 1ms if no data read */
+	struct timespec req = { .tv_nsec = 1000000 };
 
 	signal(SIGINT, sig_handler);
 	signal(SIGUSR1, sig_handler);
@@ -196,12 +190,6 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 	if (write_tracing_file("trace", "0") < 0)
 		goto out;
 
-	if (argc && perf_evlist__prepare_workload(ftrace->evlist,
-						  &ftrace->target,
-						  argv, false, true) < 0) {
-		goto out;
-	}
-
 	if (set_tracing_pid(ftrace) < 0) {
 		pr_err("failed to set ftrace pid\n");
 		goto out_reset;
@@ -233,7 +221,6 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 	}
 
 	fcntl(trace_fd, F_SETFL, O_NONBLOCK);
-	pollfd.fd = trace_fd;
 
 	if (write_tracing_file("tracing_on", "1") < 0) {
 		pr_err("can't enable tracing\n");
@@ -243,16 +230,18 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv)
 	perf_evlist__start_workload(ftrace->evlist);
 
 	while (!done) {
-		if (poll(&pollfd, 1, -1) < 0)
-			break;
+		int n = read(trace_fd, buf, sizeof(buf));
 
-		if (pollfd.revents & POLLIN) {
-			int n = read(trace_fd, buf, sizeof(buf));
-			if (n < 0)
-				break;
-			if (fwrite(buf, n, 1, stdout) != 1)
+		if (n < 0) {
+			if (errno == EINTR || errno == EAGAIN)
+				goto sleep;
+			else
 				break;
-		}
+		} else if (n == 0) {
+sleep:
+			clock_nanosleep(CLOCK_MONOTONIC, 0, &req, NULL);
+		} else if (fwrite(buf, n, 1, stdout) != 1)
+			break;
 	}
 
 	write_tracing_file("tracing_on", "0");
@@ -274,61 +263,99 @@ out:
 	return done ? 0 : -1;
 }
 
-int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused)
+static int
+__cmd_ftrace_live(struct perf_ftrace *ftrace, int argc, const char **argv)
 {
-	int ret;
-	struct perf_ftrace ftrace = {
-		.target = { .uid = UINT_MAX, },
-	};
-	const char * const ftrace_usage[] = {
-		"perf ftrace [<options>] [<command>]",
-		"perf ftrace [<options>] -- <command> [<options>]",
+	int ret = -1;
+	const char * const live_usage[] = {
+		"perf ftrace live [<options>] [<command>]",
+		"perf ftrace live [<options>] -- <command> [<options>]",
 		NULL
 	};
-	const struct option ftrace_options[] = {
-	OPT_STRING('t', "tracer", &ftrace.tracer, "tracer",
+	const struct option live_options[] = {
+	OPT_STRING('t', "tracer", &ftrace->tracer, "tracer",
 		   "tracer to use: function_graph or function"),
-	OPT_STRING('p', "pid", &ftrace.target.pid, "pid",
+	OPT_STRING('p', "pid", &ftrace->target.pid, "pid",
 		   "trace on existing process id"),
 	OPT_INCR('v', "verbose", &verbose,
 		 "be more verbose"),
-	OPT_BOOLEAN('a', "all-cpus", &ftrace.target.system_wide,
+	OPT_BOOLEAN('a', "all-cpus", &ftrace->target.system_wide,
 		    "system-wide collection from all CPUs"),
-	OPT_STRING('C', "cpu", &ftrace.target.cpu_list, "cpu",
+	OPT_STRING('C', "cpu", &ftrace->target.cpu_list, "cpu",
 		    "list of cpus to monitor"),
 	OPT_END()
 	};
 
-	argc = parse_options(argc, argv, ftrace_options, ftrace_usage,
-			    PARSE_OPT_STOP_AT_NON_OPTION);
-	if (!argc && perf_target__none(&ftrace.target))
-		usage_with_options(ftrace_usage, ftrace_options);
+	argc = parse_options(argc, argv, live_options, live_usage,
+			     PARSE_OPT_STOP_AT_NON_OPTION);
+	if (!argc && perf_target__none(&ftrace->target))
+		usage_with_options(live_usage, live_options);
 
-	ret = perf_target__validate(&ftrace.target);
+	ret = perf_target__validate(&ftrace->target);
 	if (ret) {
 		char errbuf[512];
 
-		perf_target__strerror(&ftrace.target, ret, errbuf, 512);
+		perf_target__strerror(&ftrace->target, ret, errbuf, 512);
 		pr_err("%s\n", errbuf);
 		return -EINVAL;
 	}
 
-	ftrace.evlist = perf_evlist__new();
-	if (ftrace.evlist == NULL)
+	ftrace->evlist = perf_evlist__new();
+	if (ftrace->evlist == NULL)
 		return -ENOMEM;
 
-	ret = perf_evlist__create_maps(ftrace.evlist, &ftrace.target);
+	ret = perf_evlist__create_maps(ftrace->evlist, &ftrace->target);
 	if (ret < 0)
-		goto out_delete_evlist;
+		goto out;
+
+	if (ftrace->tracer == NULL)
+		ftrace->tracer = DEFAULT_TRACER;
+
+	if (argc && perf_evlist__prepare_workload(ftrace->evlist,
+						  &ftrace->target,
+						  argv, false, true) < 0)
+		goto out_maps;
+
+	ret = do_ftrace_live(ftrace);
+
+out_maps:
+	perf_evlist__delete_maps(ftrace->evlist);
+out:
+	perf_evlist__delete(ftrace->evlist);
+
+	return ret;
+}
+
+int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused)
+{
+	int ret;
+	struct perf_ftrace ftrace = {
+		.target = { .uid = UINT_MAX, },
+	};
+	const char * const ftrace_usage[] = {
+		"perf ftrace {live} [<options>] [<command>]",
+		"perf ftrace {live} [<options>] -- <command> [<options>]",
+		NULL
+	};
+	const struct option ftrace_options[] = {
+	OPT_END()
+	};
 
-	if (ftrace.tracer == NULL)
-		ftrace.tracer = DEFAULT_TRACER;
+	argc = parse_options(argc, argv, ftrace_options, ftrace_usage,
+			     PARSE_OPT_STOP_AT_NON_OPTION);
+	if (!argc)
+		usage_with_options(ftrace_usage, ftrace_options);
 
-	ret = __cmd_ftrace(&ftrace, argc, argv);
+	if (geteuid() != 0) {
+		pr_err("ftrace only works for root!\n");
+		return -1;
+	}
 
-	perf_evlist__delete_maps(ftrace.evlist);
-out_delete_evlist:
-	perf_evlist__delete(ftrace.evlist);
+	if (strcmp(argv[0], "live") == 0) {
+		ret = __cmd_ftrace_live(&ftrace, argc, argv);
+	} else {
+		usage_with_options(ftrace_usage, ftrace_options);
+	}
 
 	return ret;
 }
-- 
1.7.11.7

[PATCH 07/18] perf ftrace: Add 'record' sub-command

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

The ftrace record command is for saving raw ftrace buffer contents
which can be get from per_cpu/cpuX/trace_pipe_raw.

Since ftrace events are generated very frequently so single thread for
recording mostly resulted in buffer overruns.  Thus it uses per-cpu
recorder thread to prevent such cases and they save the contents to
their own files.

These per-cpu data files are saved in a directory so that they can be
easily found when needed.  I chose the default directory name as
"perf.data.dir" and the first two (i.e. "perf.data") can be changed
with -o option.  The structure of the directory looks like:

  $ tree perf.data.dir
  perf.data.dir/
  |-- perf.header
  |-- trace-cpu0.buf
  |-- trace-cpu1.buf
  |-- trace-cpu2.buf
  `-- trace-cpu3.buf

In addition to trace-cpuX.buf files, it has perf.header file also.
The perf.header file is compatible with existing perf.data format and
contains usual event information, feature mask and sample data.  The
sample data is synthesized to indicate given cpu has a record file.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-ftrace.c | 659 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 642 insertions(+), 17 deletions(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 1bb6d1ff0eb1..52bb8137daf2 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -12,6 +12,7 @@
 #include <unistd.h>
 #include <signal.h>
 #include <fcntl.h>
+#include <dirent.h>
 
 #include "util/debug.h"
 #include "util/parse-options.h"
@@ -19,14 +20,17 @@
 #include "util/target.h"
 #include "util/thread_map.h"
 #include "util/cpumap.h"
+#include "util/trace-event.h"
 
 
 #define DEFAULT_TRACER  "function_graph"
+#define DEFAULT_DIRNAME  "perf.data"
 
 struct perf_ftrace {
 	struct perf_evlist *evlist;
 	struct perf_target target;
 	const char *tracer;
+	const char *dirname;
 };
 
 static bool done;
@@ -171,40 +175,56 @@ static int reset_tracing_cpu(void)
 	return 0;
 }
 
-static int do_ftrace_live(struct perf_ftrace *ftrace)
+static int setup_tracing_files(struct perf_ftrace *ftrace)
 {
-	char *trace_file;
-	int trace_fd;
-	char buf[4096];
-	/* sleep 1ms if no data read */
-	struct timespec req = { .tv_nsec = 1000000 };
-
-	signal(SIGINT, sig_handler);
-	signal(SIGUSR1, sig_handler);
-	signal(SIGCHLD, sig_handler);
+	int ret = -1;
 
-	if (reset_tracing_files(ftrace) < 0)
+	if (reset_tracing_files(ftrace) < 0) {
+		pr_err("failed to reset tracing files\n");
 		goto out;
+	}
 
 	/* reset ftrace buffer */
-	if (write_tracing_file("trace", "0") < 0)
+	if (write_tracing_file("trace", "0") < 0) {
+		pr_err("failed to reset ftrace buffer\n");
 		goto out;
+	}
 
 	if (set_tracing_pid(ftrace) < 0) {
 		pr_err("failed to set ftrace pid\n");
-		goto out_reset;
+		goto out;
 	}
 
 	if (set_tracing_cpu(ftrace) < 0) {
 		pr_err("failed to set tracing cpumask\n");
-		goto out_reset;
+		goto out;
 	}
 
 	if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
 		pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
-		goto out_reset;
+		goto out;
 	}
 
+	ret = 0;
+out:
+	return ret;
+}
+
+static int do_ftrace_live(struct perf_ftrace *ftrace)
+{
+	char *trace_file;
+	int trace_fd;
+	char buf[4096];
+	/* sleep 1ms if no data read */
+	struct timespec req = { .tv_nsec = 1000000 };
+
+	signal(SIGINT, sig_handler);
+	signal(SIGUSR1, sig_handler);
+	signal(SIGCHLD, sig_handler);
+
+	if (setup_tracing_files(ftrace) < 0)
+		goto out_reset;
+
 	trace_file = get_tracing_file("trace_pipe");
 	if (!trace_file) {
 		pr_err("failed to open trace_pipe\n");
@@ -259,7 +279,542 @@ out_close_fd:
 	close(trace_fd);
 out_reset:
 	reset_tracing_files(ftrace);
+	return done ? 0 : -1;
+}
+
+static int alloc_ftrace_evsel(struct perf_ftrace *ftrace)
+{
+	struct perf_evsel *evsel;
+
+	if (!strcmp(ftrace->tracer, "function")) {
+		if (perf_evlist__add_newtp(ftrace->evlist, "ftrace",
+					   "function", NULL) < 0) {
+			pr_err("failed to allocate ftrace event\n");
+			return -1;
+		}
+	} else if (!strcmp(ftrace->tracer, "function_graph")) {
+		if (perf_evlist__add_newtp(ftrace->evlist, "ftrace",
+					   "funcgraph_entry", NULL) ||
+		    perf_evlist__add_newtp(ftrace->evlist, "ftrace",
+					   "funcgraph_exit", NULL)) {
+			pr_err("failed to allocate ftrace event\n");
+			return -1;
+		}
+	} else {
+		pr_err("Not supported tracer: %s\n", ftrace->tracer);
+		return -1;
+	}
+
+	list_for_each_entry(evsel, &ftrace->evlist->entries, node)
+		perf_evsel__set_sample_id(evsel, false);
+
+	perf_evlist__set_id_pos(ftrace->evlist);
+	return 0;
+}
+
+static void canonicalize_directory_name(const char *name)
+{
+	char *suffix = strstr(name, ".dir");
+
+	if (suffix) {
+		if (suffix[4] == '\0' || suffix[4] == '/')
+			*suffix = '\0';
+	}
+}
+
+static int remove_directory(const char *pathname)
+{
+	DIR *dir;
+	int ret = 0;
+	struct dirent *dent;
+	char namebuf[PATH_MAX];
+
+	dir = opendir(pathname);
+	if (dir == NULL)
+		return 0;
+
+	while ((dent = readdir(dir)) != NULL && !ret) {
+		struct stat statbuf;
+
+		if (dent->d_name[0] == '.')
+			continue;
+
+		scnprintf(namebuf, sizeof(namebuf), "%s/%s",
+			  pathname, dent->d_name);
+
+		ret = stat(namebuf, &statbuf);
+		if (ret < 0) {
+			pr_debug("stat failed\n");
+			break;
+		}
+
+		if (S_ISREG(statbuf.st_mode))
+			ret = unlink(namebuf);
+		else if (S_ISDIR(statbuf.st_mode))
+			ret = remove_directory(namebuf);
+		else {
+			pr_debug("unknown file.\n");
+			ret = -1;
+		}
+	}
+	closedir(dir);
+
+	if (ret < 0)
+		return ret;
+
+	return rmdir(pathname);
+}
+
+static int create_perf_header(struct perf_ftrace *ftrace)
+{
+	int err;
+	char buf[PATH_MAX];
+	struct stat statbuf;
+
+	canonicalize_directory_name(ftrace->dirname);
+
+	scnprintf(buf, sizeof(buf), "%s.dir", ftrace->dirname);
+
+	if (!stat(buf, &statbuf) && S_ISDIR(statbuf.st_mode)) {
+		/* same name already exists - rename to *.old.dir */
+		char *old_name = malloc(strlen(buf) + 5);
+		if (old_name == NULL)
+			return -1;
+
+		scnprintf(old_name, strlen(buf) + 5,
+			  "%s.old.dir", ftrace->dirname);
+
+		if (remove_directory(old_name) < 0) {
+			perror("rmdir");
+			return -1;
+		}
+
+		if (rename(buf, old_name) < 0) {
+			perror("rename");
+			free(old_name);
+			return -1;
+		}
+
+		free(old_name);
+	}
+
+	err = mkdir(buf, 0755);
+	if (err < 0) {
+		perror("mkdir");
+		return -1;
+	}
+
+	strcat(buf, "/perf.header");
+
+	err = open(buf, O_RDWR | O_CREAT | O_TRUNC, 0644);
+	return err;
+}
+
+static void sig_dummy_handler(int sig __maybe_unused)
+{
+	while (!done)
+		continue;
+}
+
+enum {
+	RECORD_STATE__ERROR = -1,
+	RECORD_STATE__INIT,
+	RECORD_STATE__READY,
+	RECORD_STATE__DONE,
+};
+
+struct ftrace_record_arg {
+	struct perf_ftrace *ftrace;
+	int cpu;
+	int state;
+	pthread_t id;
+	struct list_head node;
+};
+
+static int recorder_count;
+pthread_cond_t recorder_ready_cond = PTHREAD_COND_INITIALIZER;
+pthread_cond_t recorder_start_cond = PTHREAD_COND_INITIALIZER;
+pthread_mutex_t recorder_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+static void *record_ftrace_raw_buffer(void *arg)
+{
+	struct ftrace_record_arg *fra = arg;
+	char buf[4096];
+	char *trace_file;
+	int trace_fd;
+	int output_fd;
+	off_t byte_written = 0;
+	sigset_t sigmask;
+	/* sleep 1ms if no data read */
+	struct timespec req = { .tv_nsec = 1000000 };
+
+	fra->state = RECORD_STATE__ERROR;
+
+	snprintf(buf, sizeof(buf), "per_cpu/cpu%d/trace_pipe_raw", fra->cpu);
+
+	trace_file = get_tracing_file(buf);
+	if (!trace_file) {
+		pr_err("failed to get trace_pipe_raw\n");
+		goto out;
+	}
+
+	trace_fd = open(trace_file, O_RDONLY);
+
+	put_tracing_file(trace_file);
+
+	if (trace_fd < 0) {
+		pr_err("failed to open trace_pipe_raw\n");
+		goto out;
+	}
+
+	snprintf(buf, sizeof(buf), "%s.dir/trace-cpu%d.buf",
+		 fra->ftrace->dirname, fra->cpu);
+
+	output_fd = open(buf, O_WRONLY|O_CREAT|O_TRUNC, 0644);
+	if (output_fd < 0) {
+		pr_err("failed to open output file\n");
+		goto out_close;
+	}
+
+	fra->state = RECORD_STATE__READY;
+
+	/*
+	 * block all signals but SIGUSR2.
+	 * It'll be used to unblock a recorder to finish.
+	 */
+	sigfillset(&sigmask);
+	sigdelset(&sigmask, SIGUSR2);
+	pthread_sigmask(SIG_SETMASK, &sigmask,NULL);
+
+	signal(SIGUSR2, sig_dummy_handler);
+
+	fcntl(trace_fd, F_SETFL, O_NONBLOCK);
+
+	/* Now I'm ready */
+	pthread_mutex_lock(&recorder_mutex);
+	recorder_count++;
+	pthread_cond_signal(&recorder_ready_cond);
+	pthread_cond_wait(&recorder_start_cond, &recorder_mutex);
+	pthread_mutex_unlock(&recorder_mutex);
+
+	pr_debug2("now recording for cpu%d\n", fra->cpu);
+
+	while (!done) {
+		int n = read(trace_fd, buf, sizeof(buf));
+
+		if (n < 0) {
+			if (errno == EINTR || errno == EAGAIN)
+				goto sleep;
+			else
+				break;
+		} else if (n == 0) {
+sleep:
+			clock_nanosleep(CLOCK_MONOTONIC, 0, &req, NULL);
+		} else if (write(output_fd, buf, n) != n)
+			break;
+
+		byte_written += n;
+	}
+
+	/* read remaining buffer contents */
+	while (true) {
+		int n = read(trace_fd, buf, sizeof(buf));
+
+		if (n < 0) {
+			if (errno == EINTR || errno == EAGAIN)
+				break;
+			perror("flush read");
+			goto out_close2;
+		} else if (n == 0)
+			break;
+
+		if (write(output_fd, buf, n) != n) {
+			perror("flush write");
+			goto out_close2;
+		}
+
+		byte_written += n;
+	}
+	fra->state = RECORD_STATE__DONE;
+
+out_close2:
+	close(output_fd);
+out_close:
+	close(trace_fd);
 out:
+	if (fra->state == RECORD_STATE__ERROR) {
+		/*
+		 * We need to update recorder_count in this case also
+		 * in order to prevent deadlocking in the main thread.
+		 */
+		pthread_mutex_lock(&recorder_mutex);
+		recorder_count++;
+		pthread_cond_signal(&recorder_ready_cond);
+		pthread_mutex_unlock(&recorder_mutex);
+	}
+
+	pr_debug2("done with %ld bytes\n", (long)byte_written);
+	return fra;
+}
+
+static void *synthesize_raw_data(struct perf_evsel *evsel)
+{
+	void *data = NULL;
+	u32 data_size;
+
+	if (!strcmp(evsel->tp_format->name, "function")) {
+		struct {
+			unsigned short common_type;
+			unsigned char common_flags;
+			unsigned char common_preempt_count;
+			int common_pid;
+			int common_padding;
+
+			unsigned long ip;
+			unsigned long parent_ip;
+		} function_format = {
+			.common_type = evsel->attr.config,
+		};
+
+		data_size = sizeof(function_format);
+
+		data = malloc(data_size + sizeof(u32));
+		if (data == NULL)
+			return NULL;
+
+		memcpy(data, &data_size, sizeof(data_size));
+		memcpy(data + sizeof(data_size), &function_format,
+		       sizeof(function_format));
+	} else if (!strcmp(evsel->tp_format->name, "funcgraph_entry")) {
+		struct {
+			unsigned short common_type;
+			unsigned char common_flags;
+			unsigned char common_preempt_count;
+			int common_pid;
+			int common_padding;
+
+			unsigned long func;
+			int depth;
+		} funcgraph_entry_format = {
+			.common_type = evsel->attr.config,
+		};
+
+		data_size = sizeof(funcgraph_entry_format);
+
+		data = malloc(data_size + sizeof(u32));
+		if (data == NULL)
+			return NULL;
+
+		memcpy(data, &data_size, sizeof(data_size));
+		memcpy(data + sizeof(data_size), &funcgraph_entry_format,
+		       sizeof(funcgraph_entry_format));
+	}
+	return data;
+}
+
+static int do_ftrace_record(struct perf_ftrace *ftrace)
+{
+	int i, err, feat;
+	int perf_fd;
+	LIST_HEAD(recorders);
+	struct perf_session *session;
+	struct ftrace_record_arg *fra, *tmp;
+
+	signal(SIGINT, sig_handler);
+	signal(SIGUSR1, sig_handler);
+	signal(SIGCHLD, sig_handler);
+
+	if (setup_tracing_files(ftrace) < 0)
+		goto out_reset;
+
+	alloc_ftrace_evsel(ftrace);
+
+	perf_fd = create_perf_header(ftrace);
+	if (perf_fd < 0) {
+		pr_err("failed to create perf directory\n");
+		goto out_reset;
+	}
+
+	/* just use a dummy session for header recording */
+	session = zalloc(sizeof(*session));
+	if (session == NULL) {
+		pr_err("failed to allocate perf session\n");
+		goto out_close;
+	}
+	session->evlist = ftrace->evlist;
+
+	for (feat = HEADER_FIRST_FEATURE; feat < HEADER_LAST_FEATURE; feat++)
+		perf_header__set_feat(&session->header, feat);
+
+	perf_header__clear_feat(&session->header, HEADER_BUILD_ID);
+	perf_header__clear_feat(&session->header, HEADER_BRANCH_STACK);
+	perf_header__clear_feat(&session->header, HEADER_PMU_MAPPINGS);
+	perf_header__clear_feat(&session->header, HEADER_GROUP_DESC);
+
+	err = perf_session__write_header(session, ftrace->evlist,
+					 perf_fd, false);
+	if (err < 0) {
+		pr_err("failed to write perf header\n");
+		goto out_session;
+	}
+
+	/*
+	 * We record ftrace's per_cpu buffer so that it'd better having
+	 * corresponding cpu maps anyway.
+	 */
+	if (!perf_target__has_cpu(&ftrace->target)) {
+		struct cpu_map *new_map;
+
+		new_map = cpu_map__new(NULL);
+		if (new_map == NULL) {
+			pr_err("failed to create new cpu map\n");
+			goto out_session;
+		}
+
+		/* replace existing cpu map */
+		cpu_map__delete(ftrace->evlist->cpus);
+		ftrace->evlist->cpus = new_map;
+	}
+
+	for (i = 0; i < cpu_map__nr(ftrace->evlist->cpus); i++) {
+		fra = malloc(sizeof(*fra));
+		if (fra == NULL) {
+			pr_err("not enough memory!\n");
+			goto out_fra;
+		}
+
+		fra->ftrace = ftrace;
+		fra->cpu = ftrace->evlist->cpus->map[i];
+		fra->state = RECORD_STATE__INIT;
+		list_add_tail(&fra->node, &recorders);
+
+		err = pthread_create(&fra->id, NULL,
+				     record_ftrace_raw_buffer, fra);
+		if (err < 0) {
+			pr_err("failed to create recorder thread\n");
+			goto out_fra;
+		}
+	}
+
+	/* wait for all recorders ready */
+	pthread_mutex_lock(&recorder_mutex);
+	while (recorder_count != cpu_map__nr(ftrace->evlist->cpus))
+		pthread_cond_wait(&recorder_ready_cond, &recorder_mutex);
+	pthread_mutex_unlock(&recorder_mutex);
+
+	list_for_each_entry(fra, &recorders, node) {
+		if (fra->state != RECORD_STATE__READY) {
+			pr_err("cpu%d: failed to start recorder", fra->cpu);
+			goto out_fra;
+		}
+	}
+
+	if (write_tracing_file("tracing_on", "1") < 0) {
+		pr_err("can't enable tracing\n");
+		goto out_fra;
+	}
+
+	perf_evlist__start_workload(ftrace->evlist);
+
+	pr_debug2("start recording per cpu buffers\n");
+	pthread_mutex_lock(&recorder_mutex);
+	pthread_cond_broadcast(&recorder_start_cond);
+	pthread_mutex_unlock(&recorder_mutex);
+
+	/* wait for signal/finish */
+	pause();
+
+	if (write_tracing_file("tracing_on", "0") < 0) {
+		pr_err("can't disable tracing\n");
+		goto out_fra;
+	}
+
+	/* signal recorders to terminate */
+	list_for_each_entry(fra, &recorders, node) {
+		pr_debug2("killing recorder thread for cpu%d\n", fra->cpu);
+		pthread_kill(fra->id, SIGUSR2);
+	}
+
+	list_for_each_entry(fra, &recorders, node)
+		pthread_join(fra->id, NULL);
+
+	/* synthesize sample data */
+	list_for_each_entry(fra, &recorders, node) {
+		struct perf_evsel *evsel = perf_evlist__first(ftrace->evlist);
+		union perf_event event = {
+			.sample = {
+				.header = {
+					.type = PERF_RECORD_SAMPLE,
+					.misc = PERF_RECORD_MISC_KERNEL,
+					.size = sizeof(event.sample.header) +
+						evsel->sample_size,
+				},
+			},
+		};
+		struct perf_sample sample = {
+			.cpu = fra->cpu,
+			.period = 1,
+		};
+		void *raw_data;
+		u32 raw_size;
+		int orig_size;
+
+		if (fra->state != RECORD_STATE__DONE) {
+			pr_warning("recorder failed for some reason on cpu%d\n",
+				   fra->cpu);
+			continue;
+		}
+
+		perf_event__synthesize_sample(&event, evsel->attr.sample_type,
+					      evsel->attr.sample_regs_user,
+					      evsel->attr.read_format,
+					      &sample, false);
+
+		raw_data = synthesize_raw_data(evsel);
+		if (raw_data == NULL) {
+			pr_err("synthesizing raw sample failed\n");
+			goto out_fra;
+		}
+
+		/*
+		 * start of raw data is the size of raw data excluding itself.
+		 */
+		raw_size = sizeof(u32) + (*(u32 *) raw_data);
+
+		orig_size = event.sample.header.size;
+		event.sample.header.size += raw_size;
+
+		err = write(perf_fd, &event.sample, orig_size);
+		if (err != orig_size) {
+			pr_err("write error occurred\n");
+			free(raw_data);
+			goto out_fra;
+		}
+
+		err = write(perf_fd, raw_data, raw_size);
+		free(raw_data);
+
+		if (err != (int)raw_size) {
+			pr_err("write error occurred\n");
+			goto out_fra;
+		}
+
+		session->header.data_size += event.sample.header.size;
+	}
+
+	perf_session__write_header(session, ftrace->evlist, perf_fd, true);
+
+out_fra:
+	list_for_each_entry_safe(fra, tmp, &recorders, node) {
+		list_del(&fra->node);
+		free(fra);
+	}
+out_session:
+	free(session);
+out_close:
+	close(perf_fd);
+out_reset:
+	reset_tracing_files(ftrace);
 	return done ? 0 : -1;
 }
 
@@ -326,6 +881,74 @@ out:
 	return ret;
 }
 
+static int
+__cmd_ftrace_record(struct perf_ftrace *ftrace, int argc, const char **argv)
+{
+	int ret = -1;
+	const char * const record_usage[] = {
+		"perf ftrace record [<options>] [<command>]",
+		"perf ftrace record [<options>] -- <command> [<options>]",
+		NULL
+	};
+	const struct option record_options[] = {
+	OPT_STRING('t', "tracer", &ftrace->tracer, "tracer",
+		   "tracer to use: function_graph or function"),
+	OPT_STRING('p', "pid", &ftrace->target.pid, "pid",
+		   "trace on existing process id"),
+	OPT_INCR('v', "verbose", &verbose,
+		 "be more verbose"),
+	OPT_BOOLEAN('a', "all-cpus", &ftrace->target.system_wide,
+		    "system-wide collection from all CPUs"),
+	OPT_STRING('C', "cpu", &ftrace->target.cpu_list, "cpu",
+		    "list of cpus to monitor"),
+	OPT_STRING('o', "output", &ftrace->dirname, "dirname",
+		   "input directory name to use (default: perf.data)"),
+	OPT_END()
+	};
+
+	argc = parse_options(argc, argv, record_options, record_usage,
+			     PARSE_OPT_STOP_AT_NON_OPTION);
+	if (!argc && perf_target__none(&ftrace->target))
+		usage_with_options(record_usage, record_options);
+
+	ret = perf_target__validate(&ftrace->target);
+	if (ret) {
+		char errbuf[512];
+
+		perf_target__strerror(&ftrace->target, ret, errbuf, 512);
+		pr_err("%s\n", errbuf);
+		return -EINVAL;
+	}
+
+	ftrace->evlist = perf_evlist__new();
+	if (ftrace->evlist == NULL)
+		return -ENOMEM;
+
+	ret = perf_evlist__create_maps(ftrace->evlist, &ftrace->target);
+	if (ret < 0)
+		goto out;
+
+	if (ftrace->tracer == NULL)
+		ftrace->tracer = DEFAULT_TRACER;
+
+	if (ftrace->dirname == NULL)
+		ftrace->dirname = DEFAULT_DIRNAME;
+
+	if (argc && perf_evlist__prepare_workload(ftrace->evlist,
+						  &ftrace->target,
+						  argv, false, true) < 0)
+		goto out_maps;
+
+	ret = do_ftrace_record(ftrace);
+
+out_maps:
+	perf_evlist__delete_maps(ftrace->evlist);
+out:
+	perf_evlist__delete(ftrace->evlist);
+
+	return ret;
+}
+
 int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused)
 {
 	int ret;
@@ -333,8 +956,8 @@ int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused)
 		.target = { .uid = UINT_MAX, },
 	};
 	const char * const ftrace_usage[] = {
-		"perf ftrace {live} [<options>] [<command>]",
-		"perf ftrace {live} [<options>] -- <command> [<options>]",
+		"perf ftrace {live|record} [<options>] [<command>]",
+		"perf ftrace {live|record} [<options>] -- <command> [<options>]",
 		NULL
 	};
 	const struct option ftrace_options[] = {
@@ -353,6 +976,8 @@ int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused)
 
 	if (strcmp(argv[0], "live") == 0) {
 		ret = __cmd_ftrace_live(&ftrace, argc, argv);
+	} else 	if (strncmp(argv[0], "rec", 3) == 0) {
+		ret = __cmd_ftrace_record(&ftrace, argc, argv);
 	} else {
 		usage_with_options(ftrace_usage, ftrace_options);
 	}
-- 
1.7.11.7

[PATCH 08/18] perf ftrace: Add 'show' sub-command

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

The ftrace show subcommand is for viewing recorded ftrace files.  It
enters perf.data.dir directory and open perf.header file to find out
necessary information.  And then read out per-cpu trace records using
kbuffer helper and print them to stdout in time order.

It only shows its basic form so function graph doesn't show duration/
overhead and no leaf entry handling is provided yet.  Maybe it can be
handled by a proper plugin in the libtraceevent.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-ftrace.c | 435 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 433 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 52bb8137daf2..3a12fb9d4b94 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -13,6 +13,7 @@
 #include <signal.h>
 #include <fcntl.h>
 #include <dirent.h>
+#include <sys/mman.h>
 
 #include "util/debug.h"
 #include "util/parse-options.h"
@@ -21,6 +22,8 @@
 #include "util/thread_map.h"
 #include "util/cpumap.h"
 #include "util/trace-event.h"
+#include "../lib/traceevent/kbuffer.h"
+#include "../lib/traceevent/event-parse.h"
 
 
 #define DEFAULT_TRACER  "function_graph"
@@ -31,6 +34,7 @@ struct perf_ftrace {
 	struct perf_target target;
 	const char *tracer;
 	const char *dirname;
+	struct pevent *pevent;
 };
 
 static bool done;
@@ -819,6 +823,379 @@ out_reset:
 }
 
 static int
+function_handler(struct trace_seq *s, struct pevent_record *record,
+		 struct event_format *event, void *context __maybe_unused)
+{
+	struct pevent *pevent = event->pevent;
+	unsigned long long function;
+	const char *func;
+
+	if (pevent_get_field_val(s, event, "ip", record, &function, 1))
+		return trace_seq_putc(s, '!');
+
+	func = pevent_find_function(pevent, function);
+	if (func)
+		trace_seq_printf(s, "%s <-- ", func);
+	else
+		trace_seq_printf(s, "0x%llx", function);
+
+	if (pevent_get_field_val(s, event, "parent_ip", record, &function, 1))
+		return trace_seq_putc(s, '!');
+
+	func = pevent_find_function(pevent, function);
+	if (func)
+		trace_seq_printf(s, "%s", func);
+	else
+		trace_seq_printf(s, "0x%llx", function);
+
+	trace_seq_putc(s, '\n');
+	return 0;
+}
+
+#define TRACE_GRAPH_INDENT  2
+
+static int
+fgraph_ent_handler(struct trace_seq *s, struct pevent_record *record,
+		   struct event_format *event, void *context __maybe_unused)
+{
+	unsigned long long depth;
+	unsigned long long val;
+	const char *func;
+	int i;
+
+	if (pevent_get_field_val(s, event, "depth", record, &depth, 1))
+		return trace_seq_putc(s, '!');
+
+	/* Function */
+	for (i = 0; i < (int)(depth * TRACE_GRAPH_INDENT); i++)
+		trace_seq_putc(s, ' ');
+
+	if (pevent_get_field_val(s, event, "func", record, &val, 1))
+		return trace_seq_putc(s, '!');
+
+	func = pevent_find_function(event->pevent, val);
+
+	if (func)
+		trace_seq_printf(s, "%s() {", func);
+	else
+		trace_seq_printf(s, "%llx() {", val);
+
+	trace_seq_putc(s, '\n');
+	return 0;
+}
+
+static int
+fgraph_ret_handler(struct trace_seq *s, struct pevent_record *record,
+		   struct event_format *event, void *context __maybe_unused)
+{
+	unsigned long long depth;
+	int i;
+
+	if (pevent_get_field_val(s, event, "depth", record, &depth, 1))
+		return trace_seq_putc(s, '!');
+
+	/* Function */
+	for (i = 0; i < (int)(depth * TRACE_GRAPH_INDENT); i++)
+		trace_seq_putc(s, ' ');
+
+	trace_seq_puts(s, "}\n");
+	return 0;
+}
+
+struct perf_ftrace_report {
+	struct perf_ftrace *ftrace;
+	struct perf_tool tool;
+};
+
+struct ftrace_report_arg {
+	struct list_head node;
+	struct pevent_record *record;
+	struct kbuffer *kbuf;
+	void *map;
+	int cpu;
+	int fd;
+	int done;
+	off_t offset;
+	off_t size;
+};
+
+static LIST_HEAD(ftrace_cpu_buffers);
+
+static int process_sample_event(struct perf_tool *tool,
+				union perf_event * event __maybe_unused,
+				struct perf_sample *sample,
+				struct perf_evsel *evsel __maybe_unused,
+				struct machine *machine __maybe_unused)
+{
+	struct perf_ftrace *ftrace;
+	struct perf_ftrace_report *report;
+	struct ftrace_report_arg *fra;
+	struct stat statbuf;
+	enum kbuffer_long_size long_size;
+	enum kbuffer_endian endian;
+	char buf[PATH_MAX];
+
+	report = container_of(tool, struct perf_ftrace_report, tool);
+	ftrace = report->ftrace;
+
+	if (perf_target__has_cpu(&ftrace->target)) {
+		int i;
+		bool found = false;
+
+		for (i = 0; i < cpu_map__nr(ftrace->evlist->cpus); i++) {
+			if ((int)sample->cpu == ftrace->evlist->cpus->map[i]) {
+				found = true;
+				break;
+			}
+		}
+		if (!found)
+			return 0;
+	}
+
+	fra = zalloc(sizeof(*fra));
+	if (fra == NULL)
+		return -1;
+
+	fra->cpu = sample->cpu;
+
+	scnprintf(buf, sizeof(buf), "%s.dir/trace-cpu%d.buf",
+		  ftrace->dirname, fra->cpu);
+
+	fra->fd = open(buf, O_RDONLY);
+	if (fra->fd < 0)
+		goto out;
+
+	if (fstat(fra->fd, &statbuf) < 0)
+		goto out_close;
+
+	fra->size = statbuf.st_size;
+	if (fra->size == 0) {
+		/* skip zero-size buffers */
+		close(fra->fd);
+		free(fra);
+		return 0;
+	}
+
+	/*
+	 * FIXME: What if pevent->page_size is smaller than current page size?
+	 */
+	fra->map = mmap(NULL, pevent_get_page_size(ftrace->pevent),
+			PROT_READ, MAP_PRIVATE, fra->fd, fra->offset);
+	if (fra->map == MAP_FAILED)
+		goto out_close;
+
+	fra->offset = 0;
+
+	if (pevent_is_file_bigendian(ftrace->pevent))
+		endian = KBUFFER_ENDIAN_BIG;
+	else
+		endian = KBUFFER_ENDIAN_LITTLE;
+
+	if (pevent_get_long_size(ftrace->pevent) == 8)
+		long_size = KBUFFER_LSIZE_8;
+	else
+		long_size = KBUFFER_LSIZE_4;
+
+	fra->kbuf = kbuffer_alloc(long_size, endian);
+	if (fra->kbuf == NULL)
+		goto out_unmap;
+
+	if (ftrace->pevent->old_format)
+		kbuffer_set_old_format(fra->kbuf);
+
+	kbuffer_load_subbuffer(fra->kbuf, fra->map);
+
+	pr_debug2("setup kbuffer for cpu%d\n", fra->cpu);
+	list_add_tail(&fra->node, &ftrace_cpu_buffers);
+	return 0;
+
+out_unmap:
+	munmap(fra->map, pevent_get_page_size(ftrace->pevent));
+out_close:
+	close(fra->fd);
+out:
+	free(fra);
+	return -1;
+}
+
+static struct pevent_record *
+get_next_ftrace_event_record(struct perf_ftrace *ftrace,
+			     struct ftrace_report_arg *fra)
+{
+	struct pevent_record *record;
+	unsigned long long ts;
+	void *data;
+
+retry:
+	data = kbuffer_read_event(fra->kbuf, &ts);
+	if (data) {
+		record = zalloc(sizeof(*record));
+		if (record == NULL) {
+			pr_err("memory allocation failure\n");
+			return NULL;
+		}
+
+		record->ts = ts;
+		record->cpu = fra->cpu;
+		record->data = data;
+		record->size = kbuffer_event_size(fra->kbuf);
+		record->record_size = kbuffer_curr_size(fra->kbuf);
+		record->offset = kbuffer_curr_offset(fra->kbuf);
+		record->missed_events = kbuffer_missed_events(fra->kbuf);
+		record->ref_count = 1;
+
+		kbuffer_next_event(fra->kbuf, NULL);
+		return record;
+	}
+
+	if (fra->done)
+		return NULL;
+
+	munmap(fra->map, pevent_get_page_size(ftrace->pevent));
+	fra->map = NULL;
+
+	fra->offset += pevent_get_page_size(ftrace->pevent);
+	if (fra->offset >= fra->size) {
+		/* EOF */
+		fra->done = 1;
+		return NULL;
+	}
+
+	fra->map = mmap(NULL, pevent_get_page_size(ftrace->pevent),
+			PROT_READ, MAP_PRIVATE, fra->fd, fra->offset);
+	if (fra->map == MAP_FAILED) {
+		pr_err("memory mapping failed\n");
+		return NULL;
+	}
+
+	kbuffer_load_subbuffer(fra->kbuf, fra->map);
+
+	goto retry;
+}
+
+static struct pevent_record *
+get_ftrace_event_record(struct perf_ftrace *ftrace,
+			struct ftrace_report_arg *fra)
+{
+	if (fra->record == NULL)
+		fra->record = get_next_ftrace_event_record(ftrace, fra);
+
+	return fra->record;
+}
+
+static struct pevent_record *get_ordered_record(struct perf_ftrace *ftrace)
+{
+	struct ftrace_report_arg *fra = NULL;
+	struct ftrace_report_arg *tmp;
+	struct pevent_record *record;
+	unsigned long long min_ts = LLONG_MAX;
+
+	list_for_each_entry(tmp, &ftrace_cpu_buffers, node) {
+		record = get_ftrace_event_record(ftrace, tmp);
+		if (record && record->ts < min_ts) {
+			min_ts = record->ts;
+			fra = tmp;
+		}
+	}
+
+	if (fra) {
+		record = fra->record;
+		fra->record = NULL;
+		return record;
+	}
+	return NULL;
+}
+
+static void free_ftrace_report_args(struct perf_ftrace *ftrace)
+{
+	struct ftrace_report_arg *fra, *tmp;
+
+	list_for_each_entry_safe(fra, tmp, &ftrace_cpu_buffers, node) {
+		list_del(&fra->node);
+
+		/* don't care about the errors */
+		munmap(fra->map, pevent_get_page_size(ftrace->pevent));
+		kbuffer_free(fra->kbuf);
+		free(fra->record);
+		close(fra->fd);
+		free(fra);
+	}
+}
+
+static int do_ftrace_show(struct perf_ftrace *ftrace)
+{
+	int ret = 0;
+	char buf[PATH_MAX];
+	struct perf_session *session;
+	struct pevent_record *record;
+	struct trace_seq seq;
+	struct perf_ftrace_report show = {
+		.ftrace = ftrace,
+		.tool = {
+			.sample = process_sample_event,
+		},
+	};
+
+	canonicalize_directory_name(ftrace->dirname);
+
+	scnprintf(buf, sizeof(buf), "%s.dir/perf.header", ftrace->dirname);
+
+	session = perf_session__new(buf, O_RDONLY, false, false, &show.tool);
+	if (session == NULL) {
+		pr_err("failed to create a session\n");
+		return -1;
+	}
+
+	ftrace->pevent = session->pevent;
+
+	pevent_register_event_handler(ftrace->pevent, -1,
+				      "ftrace", "function",
+				      function_handler, NULL);
+	pevent_register_event_handler(ftrace->pevent, -1,
+				      "ftrace", "funcgraph_entry",
+				      fgraph_ent_handler, NULL);
+	pevent_register_event_handler(ftrace->pevent, -1,
+				      "ftrace", "funcgraph_exit",
+				      fgraph_ret_handler, NULL);
+
+	if (perf_session__process_events(session, &show.tool) < 0) {
+		pr_err("failed to process events\n");
+		ret = -1;
+		goto out;
+	}
+
+	trace_seq_init(&seq);
+
+	record = get_ordered_record(ftrace);
+	while (record) {
+		int type;
+		struct event_format *event;
+
+		type = pevent_data_type(ftrace->pevent, record);
+		event = pevent_find_event(ftrace->pevent, type);
+		if (!event) {
+			pr_warning("no event found for type %d", type);
+			continue;
+		}
+
+		pevent_print_event(ftrace->pevent, &seq, record);
+		trace_seq_do_printf(&seq);
+
+		trace_seq_reset(&seq);
+
+		free(record);
+		record = get_ordered_record(ftrace);
+	}
+
+	trace_seq_destroy(&seq);
+
+out:
+	free_ftrace_report_args(ftrace);
+	perf_session__delete(session);
+	return ret;
+}
+
+static int
 __cmd_ftrace_live(struct perf_ftrace *ftrace, int argc, const char **argv)
 {
 	int ret = -1;
@@ -949,6 +1326,58 @@ out:
 	return ret;
 }
 
+static int
+__cmd_ftrace_show(struct perf_ftrace *ftrace, int argc, const char **argv)
+{
+	int ret = -1;
+	const char * const show_usage[] = {
+		"perf ftrace show [<options>]",
+		NULL
+	};
+	const struct option show_options[] = {
+	OPT_STRING('i', "input", &ftrace->dirname, "dirname",
+		   "input directory name to use (default: perf.data)"),
+	OPT_INCR('v', "verbose", &verbose,
+		 "be more verbose"),
+	OPT_STRING('C', "cpu", &ftrace->target.cpu_list, "cpu",
+		    "list of cpus to monitor"),
+	OPT_END()
+	};
+
+	argc = parse_options(argc, argv, show_options, show_usage,
+			     PARSE_OPT_STOP_AT_NON_OPTION);
+	if (argc)
+		usage_with_options(show_usage, show_options);
+
+	ret = perf_target__validate(&ftrace->target);
+	if (ret) {
+		char errbuf[512];
+
+		perf_target__strerror(&ftrace->target, ret, errbuf, 512);
+		pr_err("%s\n", errbuf);
+		return -EINVAL;
+	}
+
+	ftrace->evlist = perf_evlist__new();
+	if (ftrace->evlist == NULL)
+		return -ENOMEM;
+
+	ret = perf_evlist__create_maps(ftrace->evlist, &ftrace->target);
+	if (ret < 0)
+		goto out;
+
+	if (ftrace->dirname == NULL)
+		ftrace->dirname = DEFAULT_DIRNAME;
+
+	ret = do_ftrace_show(ftrace);
+
+	perf_evlist__delete_maps(ftrace->evlist);
+out:
+	perf_evlist__delete(ftrace->evlist);
+
+	return ret;
+}
+
 int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused)
 {
 	int ret;
@@ -956,8 +1385,8 @@ int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused)
 		.target = { .uid = UINT_MAX, },
 	};
 	const char * const ftrace_usage[] = {
-		"perf ftrace {live|record} [<options>] [<command>]",
-		"perf ftrace {live|record} [<options>] -- <command> [<options>]",
+		"perf ftrace {live|record|show} [<options>] [<command>]",
+		"perf ftrace {live|record|show} [<options>] -- <command> [<options>]",
 		NULL
 	};
 	const struct option ftrace_options[] = {
@@ -978,6 +1407,8 @@ int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused)
 		ret = __cmd_ftrace_live(&ftrace, argc, argv);
 	} else 	if (strncmp(argv[0], "rec", 3) == 0) {
 		ret = __cmd_ftrace_record(&ftrace, argc, argv);
+	} else 	if (strcmp(argv[0], "show") == 0) {
+		ret = __cmd_ftrace_show(&ftrace, argc, argv);
 	} else {
 		usage_with_options(ftrace_usage, ftrace_options);
 	}
-- 
1.7.11.7

[PATCH 09/18] perf ftrace: Add 'report' sub-command

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

The ftrace report command is for analyzing ftrace result as usual perf
report style.  Internal processing of the ftrace buffer is similar to
the 'show' sub-command but it synthesizes necessary information like
thread, dso, map and symbol from saved trace info.

It currently count number of samples as a period and it can be
extended to use calltime of funcgraph_exit in the future.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-ftrace.c | 283 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 281 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 3a12fb9d4b94..ba04a402974c 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -21,6 +21,7 @@
 #include "util/target.h"
 #include "util/thread_map.h"
 #include "util/cpumap.h"
+#include "util/sort.h"
 #include "util/trace-event.h"
 #include "../lib/traceevent/kbuffer.h"
 #include "../lib/traceevent/event-parse.h"
@@ -35,6 +36,7 @@ struct perf_ftrace {
 	const char *tracer;
 	const char *dirname;
 	struct pevent *pevent;
+	bool show_full_info;
 };
 
 static bool done;
@@ -1195,6 +1197,215 @@ out:
 	return ret;
 }
 
+struct cmdline_list {
+	struct cmdline_list	*next;
+	char			*comm;
+	int			pid;
+};
+
+struct func_list {
+	struct func_list	*next;
+	unsigned long long	addr;
+	char			*func;
+	char			*mod;
+};
+
+static int do_ftrace_report(struct perf_ftrace *ftrace)
+{
+	int ret = -1;
+	char buf[PATH_MAX];
+	unsigned long nr_samples;
+	struct perf_session *session;
+	struct perf_evsel *evsel;
+	struct pevent_record *record;
+	struct perf_ftrace_report report = {
+		.ftrace = ftrace,
+		.tool = {
+			.sample = process_sample_event,
+		},
+	};
+	struct cmdline_list *cmdline;
+	struct func_list *func;
+	struct machine *machine;
+	struct dso *dso;
+
+	canonicalize_directory_name(ftrace->dirname);
+
+	scnprintf(buf, sizeof(buf), "%s.dir/perf.header", ftrace->dirname);
+
+	session = perf_session__new(buf, O_RDONLY, false, false, &report.tool);
+	if (session == NULL) {
+		pr_err("failed to create a session\n");
+		return -1;
+	}
+
+	ftrace->pevent = session->pevent;
+
+	if (perf_session__process_events(session, &report.tool) < 0) {
+		pr_err("failed to process events\n");
+		goto out;
+	}
+
+	machine = machines__findnew(&session->machines, HOST_KERNEL_ID);
+
+	/* Synthesize thread info from saved cmdlines */
+	cmdline = ftrace->pevent->cmdlist;
+	while (cmdline) {
+		struct thread *thread;
+
+		thread = machine__findnew_thread(machine, cmdline->pid,
+						 cmdline->pid);
+		if (thread && !thread->comm_set)
+			thread__set_comm(thread, cmdline->comm);
+
+		cmdline = cmdline->next;
+	}
+
+	/* Synthesize kernel dso and symbol info from saved kallsyms */
+	func = ftrace->pevent->funclist;
+	while (func) {
+		struct symbol *sym;
+
+		scnprintf(buf, sizeof(buf), "[%s]",
+			  func->mod ? func->mod : "kernel.kallsyms");
+
+		dso = dso__kernel_findnew(machine, buf, NULL, DSO_TYPE_KERNEL);
+		if (dso == NULL) {
+			pr_debug("can't find or allocate dso %s\n", buf);
+			continue;
+		}
+
+		sym = symbol__new(func->addr, 0, STB_GLOBAL, func->func);
+		if (sym == NULL) {
+			pr_debug("failed to allocate new symbol\n");
+			continue;
+		}
+		symbols__insert(&dso->symbols[MAP__FUNCTION], sym);
+
+		func = func->next;
+	}
+
+	/* Generate kernel maps */
+	list_for_each_entry(dso, &machine->kernel_dsos, node) {
+		struct map *map = map__new2(0, dso, MAP__FUNCTION);
+		if (map == NULL) {
+			pr_debug("failed to allocate new map\n");
+			goto out;
+		}
+
+		symbols__fixup_end(&dso->symbols[MAP__FUNCTION]);
+		map__fixup_start(map);
+		map__fixup_end(map);
+
+		dso__set_loaded(dso, MAP__FUNCTION);
+
+		map_groups__insert(&machine->kmaps, map);
+		if (strcmp(dso->name, "[kernel.kallsyms]") == 0)
+			machine->vmlinux_maps[MAP__FUNCTION] = map;
+	}
+
+	/* FIXME: no need to get ordered */
+	record = get_ordered_record(ftrace);
+	while (record) {
+		int type;
+		struct addr_location al;
+		union perf_event event = {
+			.header = {
+				.misc = PERF_RECORD_MISC_KERNEL,
+			},
+		};
+		struct perf_sample sample = {
+			.cpu = record->cpu,
+			.raw_data = record->data,
+			.period = 1,
+		};
+		struct format_field *field;
+		unsigned long long val;
+
+		type = pevent_data_type(ftrace->pevent, record);
+		evsel = perf_evlist__find_tracepoint_by_id(session->evlist,
+							   type);
+		if (evsel == NULL) {
+			pr_warning("no event found for type %d\n", type);
+			continue;
+		}
+
+		sample.pid = pevent_data_pid(ftrace->pevent, record);
+
+		if (!strcmp(perf_evsel__name(evsel), "ftrace:function"))
+			field = pevent_find_field(evsel->tp_format, "ip");
+		else
+			field = pevent_find_field(evsel->tp_format, "func");
+
+		if (pevent_read_number_field(field, record->data, &val) < 0) {
+			pr_err("failed to parse function address\n");
+			goto out;
+		}
+		sample.ip = val;
+
+		if (perf_event__preprocess_sample(&event, machine, &al,
+						  &sample) < 0) {
+			pr_err("problem processing %d event, skipping it.\n",
+				event.header.type);
+			goto out;
+		}
+
+		/* TODO: update sample.period using calltime */
+		if (!__hists__add_entry(&evsel->hists, &al, NULL,
+					sample.period, 0, 0)) {
+			pr_err("failed to add a hist entry\n");
+			goto out;
+		}
+
+		evsel->hists.stats.total_period += sample.period;
+		hists__inc_nr_events(&evsel->hists, PERF_RECORD_SAMPLE);
+
+		free(record);
+		record = get_ordered_record(ftrace);
+	}
+	ret = 0;
+
+	perf_session__fprintf_info(session, stdout, ftrace->show_full_info);
+
+	nr_samples = 0;
+	list_for_each_entry(evsel, &session->evlist->entries, node) {
+		struct hists *hists = &evsel->hists;
+
+		hists__collapse_resort(hists);
+		hists__output_resort(&evsel->hists);
+		nr_samples += hists->stats.nr_events[PERF_RECORD_SAMPLE];
+	}
+
+	if (nr_samples == 0) {
+		pr_warning("The %s file has no samples!\n", session->filename);
+		goto out;
+	}
+
+	list_for_each_entry(evsel, &session->evlist->entries, node) {
+		struct hists *hists = &evsel->hists;
+		const char *evname = perf_evsel__name(evsel);
+		u64 nr_events = hists->stats.total_period;
+		char unit;
+
+		nr_samples = hists->stats.nr_events[PERF_RECORD_SAMPLE];
+		nr_samples = convert_unit(nr_samples, &unit);
+		fprintf(stdout, "# Samples: %lu%c", nr_samples, unit);
+		if (evname != NULL)
+			fprintf(stdout, " of event '%s'", evname);
+
+		fprintf(stdout, "\n# Event count (approx.): %" PRIu64, nr_events);
+		fprintf(stdout, "\n#\n");
+
+		hists__fprintf(hists, true, 0, 0, 0.0, stdout);
+		fprintf(stdout, "\n\n");
+	}
+
+out:
+	free_ftrace_report_args(ftrace);
+	perf_session__delete(session);
+	return ret;
+}
+
 static int
 __cmd_ftrace_live(struct perf_ftrace *ftrace, int argc, const char **argv)
 {
@@ -1378,6 +1589,72 @@ out:
 	return ret;
 }
 
+static int
+__cmd_ftrace_report(struct perf_ftrace *ftrace, int argc, const char **argv)
+{
+	int ret = -1;
+	const char * const report_usage[] = {
+		"perf ftrace report [<options>]",
+		NULL
+	};
+	const struct option report_options[] = {
+	OPT_STRING('i', "input", &ftrace->dirname, "dirname",
+		   "input directory name to use (default: perf.data)"),
+	OPT_INCR('v', "verbose", &verbose,
+		 "be more verbose"),
+	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
+		    "dump raw trace in ASCII"),
+	OPT_STRING('C', "cpu", &ftrace->target.cpu_list, "cpu",
+		    "list of cpus to monitor"),
+	OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
+		   "sort by key(s): pid, comm, dso, symbol, cpu"),
+	OPT_BOOLEAN('I', "show-info", &ftrace->show_full_info,
+		    "Display extended information like cpu/numa topology"),
+	OPT_END()
+	};
+
+	argc = parse_options(argc, argv, report_options, report_usage,
+			     PARSE_OPT_STOP_AT_NON_OPTION);
+	if (argc)
+		usage_with_options(report_usage, report_options);
+
+	ret = perf_target__validate(&ftrace->target);
+	if (ret) {
+		char errbuf[512];
+
+		perf_target__strerror(&ftrace->target, ret, errbuf, 512);
+		pr_err("%s\n", errbuf);
+		return -EINVAL;
+	}
+
+	ftrace->evlist = perf_evlist__new();
+	if (ftrace->evlist == NULL)
+		return -ENOMEM;
+
+	ret = perf_evlist__create_maps(ftrace->evlist, &ftrace->target);
+	if (ret < 0)
+		goto out;
+
+	if (ftrace->dirname == NULL)
+		ftrace->dirname = DEFAULT_DIRNAME;
+
+	perf_hpp__init();
+
+	setup_sorting();
+
+	symbol_conf.exclude_other = false;
+	symbol_conf.try_vmlinux_path = false;
+	symbol__init();
+
+	ret = do_ftrace_report(ftrace);
+
+	perf_evlist__delete_maps(ftrace->evlist);
+out:
+	perf_evlist__delete(ftrace->evlist);
+
+	return ret;
+}
+
 int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused)
 {
 	int ret;
@@ -1385,8 +1662,8 @@ int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused)
 		.target = { .uid = UINT_MAX, },
 	};
 	const char * const ftrace_usage[] = {
-		"perf ftrace {live|record|show} [<options>] [<command>]",
-		"perf ftrace {live|record|show} [<options>] -- <command> [<options>]",
+		"perf ftrace {live|record|show|report} [<options>] [<command>]",
+		"perf ftrace {live|record|show|report} [<options>] -- <command> [<options>]",
 		NULL
 	};
 	const struct option ftrace_options[] = {
@@ -1409,6 +1686,8 @@ int cmd_ftrace(int argc, const char **argv, const char *prefix __maybe_unused)
 		ret = __cmd_ftrace_record(&ftrace, argc, argv);
 	} else 	if (strcmp(argv[0], "show") == 0) {
 		ret = __cmd_ftrace_show(&ftrace, argc, argv);
+	} else 	if (strncmp(argv[0], "rep", 3) == 0) {
+		ret = __cmd_ftrace_report(&ftrace, argc, argv);
 	} else {
 		usage_with_options(ftrace_usage, ftrace_options);
 	}
-- 
1.7.11.7

[PATCH 10/18] perf ftrace: Add dump_printf() for low-level debugging

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

For reusability, rename trace_event() to dump_raw_event() and pass
size as an argument.  And use it in do_ftrace_report() to show raw
data of ftrace entries.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-ftrace.c | 6 ++++++
 tools/perf/util/debug.c     | 8 ++++----
 tools/perf/util/debug.h     | 2 +-
 tools/perf/util/session.c   | 2 +-
 4 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index ba04a402974c..676b2aa7590f 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -1350,6 +1350,12 @@ static int do_ftrace_report(struct perf_ftrace *ftrace)
 			goto out;
 		}
 
+		dump_printf(" .... event: %s\n", perf_evsel__name(evsel));
+		dump_raw_event(record, record->size);
+		dump_printf("%3d %llu %#llx [%#x]\n\n",
+			    record->cpu, record->ts, record->offset,
+			    record->size);
+
 		/* TODO: update sample.period using calltime */
 		if (!__hists__add_entry(&evsel->hists, &al, NULL,
 					sample.period, 0, 0)) {
diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index 399e74c34c1a..2c42aaed4528 100644
--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -47,7 +47,7 @@ int dump_printf(const char *fmt, ...)
 	return ret;
 }
 
-void trace_event(union perf_event *event)
+void dump_raw_event(void *event, int size)
 {
 	unsigned char *raw_event = (void *)event;
 	const char *color = PERF_COLOR_BLUE;
@@ -58,9 +58,9 @@ void trace_event(union perf_event *event)
 
 	printf(".");
 	color_fprintf(stdout, color, "\n. ... raw event: size %d bytes\n",
-		      event->header.size);
+		      size);
 
-	for (i = 0; i < event->header.size; i++) {
+	for (i = 0; i < size; i++) {
 		if ((i & 15) == 0) {
 			printf(".");
 			color_fprintf(stdout, color, "  %04x: ", i);
@@ -68,7 +68,7 @@ void trace_event(union perf_event *event)
 
 		color_fprintf(stdout, color, " %02x", raw_event[i]);
 
-		if (((i & 15) == 15) || i == event->header.size-1) {
+		if (((i & 15) == 15) || i == size-1) {
 			color_fprintf(stdout, color, "  ");
 			for (j = 0; j < 15-(i & 15); j++)
 				color_fprintf(stdout, color, "   ");
diff --git a/tools/perf/util/debug.h b/tools/perf/util/debug.h
index efbd98805ad0..9cebb0cdb7bd 100644
--- a/tools/perf/util/debug.h
+++ b/tools/perf/util/debug.h
@@ -12,7 +12,7 @@ extern int verbose;
 extern bool quiet, dump_trace;
 
 int dump_printf(const char *fmt, ...) __attribute__((format(printf, 1, 2)));
-void trace_event(union perf_event *event);
+void dump_raw_event(void *event, int size);
 
 int ui__error(const char *format, ...) __attribute__((format(printf, 1, 2)));
 int ui__warning(const char *format, ...) __attribute__((format(printf, 1, 2)));
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index d1e449534b33..a714265ea0c3 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -832,7 +832,7 @@ static void dump_event(struct perf_session *session, union perf_event *event,
 	printf("\n%#" PRIx64 " [%#x]: event: %d\n",
 	       file_offset, event->header.size, event->header.type);
 
-	trace_event(event);
+	dump_raw_event(event, event->header.size);
 
 	if (sample)
 		perf_session__print_tstamp(session, event, sample);
-- 
1.7.11.7

[PATCH 11/18] perf ftrace: Use pager for displaying result

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

It's convenient to use pager when seeing many lines of result.

Note that setup_pager() should be called after perf_evlist__
prepare_workload() since they can interfere each other regarding
shared stdio streams.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-ftrace.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 676b2aa7590f..83ed6d797087 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -227,6 +227,7 @@ static int do_ftrace_live(struct perf_ftrace *ftrace)
 	signal(SIGINT, sig_handler);
 	signal(SIGUSR1, sig_handler);
 	signal(SIGCHLD, sig_handler);
+	signal(SIGPIPE, sig_handler);
 
 	if (setup_tracing_files(ftrace) < 0)
 		goto out_reset;
@@ -1465,6 +1466,8 @@ __cmd_ftrace_live(struct perf_ftrace *ftrace, int argc, const char **argv)
 						  argv, false, true) < 0)
 		goto out_maps;
 
+	setup_pager();
+
 	ret = do_ftrace_live(ftrace);
 
 out_maps:
@@ -1586,6 +1589,8 @@ __cmd_ftrace_show(struct perf_ftrace *ftrace, int argc, const char **argv)
 	if (ftrace->dirname == NULL)
 		ftrace->dirname = DEFAULT_DIRNAME;
 
+	setup_pager();
+
 	ret = do_ftrace_show(ftrace);
 
 	perf_evlist__delete_maps(ftrace->evlist);
@@ -1646,6 +1651,7 @@ __cmd_ftrace_report(struct perf_ftrace *ftrace, int argc, const char **argv)
 
 	perf_hpp__init();
 
+	setup_pager();
 	setup_sorting();
 
 	symbol_conf.exclude_other = false;
-- 
1.7.11.7

[PATCH 12/18] perf ftrace: Cleanup using ftrace_setup/teardown()

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

The ftrace sub-commands share some common code so that factor it out
to ftrace_setup() and ftrace_teardown() helpers.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-ftrace.c | 172 +++++++++++++++++---------------------------
 1 file changed, 65 insertions(+), 107 deletions(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 83ed6d797087..fa7a9c59e228 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -1413,10 +1413,59 @@ out:
 	return ret;
 }
 
+static int ftrace_setup(struct perf_ftrace *ftrace, int argc, const char **argv)
+{
+	int ret;
+	char errbuf[512];
+
+	ret = perf_target__validate(&ftrace->target);
+	if (ret) {
+		perf_target__strerror(&ftrace->target, ret, errbuf, 512);
+		pr_err("%s\n", errbuf);
+		return -EINVAL;
+	}
+
+	ftrace->evlist = perf_evlist__new();
+	if (ftrace->evlist == NULL)
+		return -ENOMEM;
+
+	ret = perf_evlist__create_maps(ftrace->evlist, &ftrace->target);
+	if (ret < 0)
+		goto out;
+
+	if (ftrace->tracer == NULL)
+		ftrace->tracer = DEFAULT_TRACER;
+
+	if (ftrace->dirname == NULL)
+		ftrace->dirname = DEFAULT_DIRNAME;
+
+	if (argc) {
+		ret = perf_evlist__prepare_workload(ftrace->evlist,
+						    &ftrace->target,
+						    argv, false, true);
+		if (ret < 0)
+			goto out_maps;
+	}
+	return 0;
+
+out_maps:
+	perf_evlist__delete_maps(ftrace->evlist);
+out:
+	perf_evlist__delete(ftrace->evlist);
+
+	return ret;
+}
+
+static void ftrace_teardown(struct perf_ftrace *ftrace)
+{
+	perf_evlist__delete_maps(ftrace->evlist);
+	perf_evlist__delete(ftrace->evlist);
+}
+
 static int
 __cmd_ftrace_live(struct perf_ftrace *ftrace, int argc, const char **argv)
 {
-	int ret = -1;
+	int ret;
 	const char * const live_usage[] = {
 		"perf ftrace live [<options>] [<command>]",
 		"perf ftrace live [<options>] -- <command> [<options>]",
@@ -1441,47 +1490,22 @@ __cmd_ftrace_live(struct perf_ftrace *ftrace, int argc, const char **argv)
 	if (!argc && perf_target__none(&ftrace->target))
 		usage_with_options(live_usage, live_options);
 
-	ret = perf_target__validate(&ftrace->target);
-	if (ret) {
-		char errbuf[512];
-
-		perf_target__strerror(&ftrace->target, ret, errbuf, 512);
-		pr_err("%s\n", errbuf);
-		return -EINVAL;
-	}
-
-	ftrace->evlist = perf_evlist__new();
-	if (ftrace->evlist == NULL)
-		return -ENOMEM;
-
-	ret = perf_evlist__create_maps(ftrace->evlist, &ftrace->target);
+	ret = ftrace_setup(ftrace, argc, argv);
 	if (ret < 0)
-		goto out;
-
-	if (ftrace->tracer == NULL)
-		ftrace->tracer = DEFAULT_TRACER;
-
-	if (argc && perf_evlist__prepare_workload(ftrace->evlist,
-						  &ftrace->target,
-						  argv, false, true) < 0)
-		goto out_maps;
+		return ret;
 
 	setup_pager();
 
 	ret = do_ftrace_live(ftrace);
 
-out_maps:
-	perf_evlist__delete_maps(ftrace->evlist);
-out:
-	perf_evlist__delete(ftrace->evlist);
-
+	ftrace_teardown(ftrace);
 	return ret;
 }
 
 static int
 __cmd_ftrace_record(struct perf_ftrace *ftrace, int argc, const char **argv)
 {
-	int ret = -1;
+	int ret;
 	const char * const record_usage[] = {
 		"perf ftrace record [<options>] [<command>]",
 		"perf ftrace record [<options>] -- <command> [<options>]",
@@ -1508,48 +1532,20 @@ __cmd_ftrace_record(struct perf_ftrace *ftrace, int argc, const char **argv)
 	if (!argc && perf_target__none(&ftrace->target))
 		usage_with_options(record_usage, record_options);
 
-	ret = perf_target__validate(&ftrace->target);
-	if (ret) {
-		char errbuf[512];
-
-		perf_target__strerror(&ftrace->target, ret, errbuf, 512);
-		pr_err("%s\n", errbuf);
-		return -EINVAL;
-	}
-
-	ftrace->evlist = perf_evlist__new();
-	if (ftrace->evlist == NULL)
-		return -ENOMEM;
-
-	ret = perf_evlist__create_maps(ftrace->evlist, &ftrace->target);
+	ret = ftrace_setup(ftrace, argc, argv);
 	if (ret < 0)
-		goto out;
-
-	if (ftrace->tracer == NULL)
-		ftrace->tracer = DEFAULT_TRACER;
-
-	if (ftrace->dirname == NULL)
-		ftrace->dirname = DEFAULT_DIRNAME;
-
-	if (argc && perf_evlist__prepare_workload(ftrace->evlist,
-						  &ftrace->target,
-						  argv, false, true) < 0)
-		goto out_maps;
+		return ret;
 
 	ret = do_ftrace_record(ftrace);
 
-out_maps:
-	perf_evlist__delete_maps(ftrace->evlist);
-out:
-	perf_evlist__delete(ftrace->evlist);
-
+	ftrace_teardown(ftrace);
 	return ret;
 }
 
 static int
 __cmd_ftrace_show(struct perf_ftrace *ftrace, int argc, const char **argv)
 {
-	int ret = -1;
+	int ret;
 	const char * const show_usage[] = {
 		"perf ftrace show [<options>]",
 		NULL
@@ -1569,41 +1565,22 @@ __cmd_ftrace_show(struct perf_ftrace *ftrace, int argc, const char **argv)
 	if (argc)
 		usage_with_options(show_usage, show_options);
 
-	ret = perf_target__validate(&ftrace->target);
-	if (ret) {
-		char errbuf[512];
-
-		perf_target__strerror(&ftrace->target, ret, errbuf, 512);
-		pr_err("%s\n", errbuf);
-		return -EINVAL;
-	}
-
-	ftrace->evlist = perf_evlist__new();
-	if (ftrace->evlist == NULL)
-		return -ENOMEM;
-
-	ret = perf_evlist__create_maps(ftrace->evlist, &ftrace->target);
+	ret = ftrace_setup(ftrace, argc, argv);
 	if (ret < 0)
-		goto out;
-
-	if (ftrace->dirname == NULL)
-		ftrace->dirname = DEFAULT_DIRNAME;
+		return ret;
 
 	setup_pager();
 
 	ret = do_ftrace_show(ftrace);
 
-	perf_evlist__delete_maps(ftrace->evlist);
-out:
-	perf_evlist__delete(ftrace->evlist);
-
+	ftrace_teardown(ftrace);
 	return ret;
 }
 
 static int
 __cmd_ftrace_report(struct perf_ftrace *ftrace, int argc, const char **argv)
 {
-	int ret = -1;
+	int ret;
 	const char * const report_usage[] = {
 		"perf ftrace report [<options>]",
 		NULL
@@ -1629,25 +1606,9 @@ __cmd_ftrace_report(struct perf_ftrace *ftrace, int argc, const char **argv)
 	if (argc)
 		usage_with_options(report_usage, report_options);
 
-	ret = perf_target__validate(&ftrace->target);
-	if (ret) {
-		char errbuf[512];
-
-		perf_target__strerror(&ftrace->target, ret, errbuf, 512);
-		pr_err("%s\n", errbuf);
-		return -EINVAL;
-	}
-
-	ftrace->evlist = perf_evlist__new();
-	if (ftrace->evlist == NULL)
-		return -ENOMEM;
-
-	ret = perf_evlist__create_maps(ftrace->evlist, &ftrace->target);
+	ret = ftrace_setup(ftrace, argc, argv);
 	if (ret < 0)
-		goto out;
-
-	if (ftrace->dirname == NULL)
-		ftrace->dirname = DEFAULT_DIRNAME;
+		return ret;
 
 	perf_hpp__init();
 
@@ -1660,10 +1621,7 @@ __cmd_ftrace_report(struct perf_ftrace *ftrace, int argc, const char **argv)
 
 	ret = do_ftrace_report(ftrace);
 
-	perf_evlist__delete_maps(ftrace->evlist);
-out:
-	perf_evlist__delete(ftrace->evlist);
-
+	ftrace_teardown(ftrace);
 	return ret;
 }
 
-- 
1.7.11.7

[PATCH 13/18] perf tools: Add document for perf-ftrace command

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/Documentation/perf-ftrace.txt | 117 +++++++++++++++++++++++++++++++
 1 file changed, 117 insertions(+)
 create mode 100644 tools/perf/Documentation/perf-ftrace.txt

diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
new file mode 100644
index 000000000000..841699f3924d
--- /dev/null
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -0,0 +1,117 @@
+perf-ftrace(1)
+==============
+
+NAME
+----
+perf-ftrace - A front end for kernel's ftrace
+
+SYNOPSIS
+--------
+[verse]
+'perf ftrace' {live|record} [<options>] [<command>]
+'perf ftrace' {show|report} [<options>]
+
+DESCRIPTION
+-----------
+This command reads the ftrace buffer and displays the trace recorded.
+
+There are several variants of perf ftrace:
+
+  'perf ftrace live <command>' to see a live trace of kernel functions
+  via trace_pipe during executing the <command>.  If <command> is not
+  specified, one of the target options (-p, -a or -C) should be given.
+  It just prints out the result to stdout and doesn't save any files.
+
+  'perf ftrace record <command>' to record trace entries of kernel
+  functions during the execution of the <command>.  Like 'perf ftrace
+  live', at least one of <command> and/or target options should be
+  given in order to start recording.  The recorded results are saved
+  under a directory ('perf.data.dir' by default) and will be used by
+  other perf-ftrace tools like 'show' and 'report'.
+
+  'perf ftrace show' to see the trace of recorded functions.  It shows
+  functions sorted by time so the end result might be interspersed if
+  there's a concurrent execution.
+
+  'perf ftrace report' to display the result in an usual perf-report
+  style - entries are sorted by given sort keys and output is resorted
+  by its overhead.
+
+OPTIONS
+-------
+<command>...::
+	Any command you can specify in a shell.
+
+-t::
+--tracer=::
+	The ftrace tracer to be used (default: function_graph).
+	Currently, only 'function' and 'function_graph' are supported
+	by 'record' command. 'live' command accepts any available
+	tracer in system and outputs trace result directly from the
+	ftrace's trace_pipe.
+
+-p::
+--pid=::
+	Record events on existing process ID (comma separated list).
+	Used by 'live' and 'record' subcommands only.
+
+-a::
+--all-cpus::
+	Force system-wide collection.  Scripts run without a <command>
+	normally use -a by default, while scripts run with a <command>
+	normally don't - this option allows the latter to be run in
+	system-wide mode.  Used by 'live' and 'record' subcommands only.
+
+-C::
+--cpu:: Only process samples for the list of CPUs provided.
+	Multiple CPUs can be provided as a comma-separated list with
+	no space: 0,1. Ranges of CPUs are specified with -: 0-2.
+	Default is to report samples on all online CPUs.
+
+-s::
+--sort=::
+	Sort histogram entries by given key(s) - multiple keys can be
+	specified in CSV format.  Following sort keys are available:
+	pid, comm, dso, symbol, cpu.
+
+	Each key has following meaning:
+
+	- comm: command (name) of the task
+	- pid: command and tid of the task
+	- dso: name of library or module executed at the time of sample
+	- symbol: name of function executed at the time of sample
+	- cpu: cpu number the task ran at the time of sample
+
+	By default, comm, dso and symbol keys are used.
+	(i.e. --sort comm,dso,symbol)
+	Used by 'report' subcommands only.
+
+-i::
+--input=::
+	Input directory name excluding '.dir' at the end.
+	(default: perf.data)
+
+-o::
+--output=::
+	Output directory name excluding '.dir' at the end.
+	(default: perf.data)
+
+-v::
+--verbose::
+	Be more verbose (show counter open errors, etc).
+
+-D::
+--dump-raw-trace::
+	Dump raw trace in ASCII.  Used by 'report' subcommands only.
+
+-I::
+--show-info::
+	Display extended information about the record.  This adds
+	information which may be very large and thus may clutter the
+	display.  It currently includes: cpu and numa topology of the
+	host system.  It can only be used with the 'report' subcommand.
+
+SEE ALSO
+--------
+linkperf:perf-record[1], linkperf:perf-report[1],
+linkperf:perf-script[1]
-- 
1.7.11.7

[PATCH 14/18] perf ftrace: Add a signal handler for SIGSEGV

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

It's for debugging purpose.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-ftrace.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index fa7a9c59e228..8fec8d6df37d 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -41,6 +41,13 @@ struct perf_ftrace {
 
 static bool done;
 
+static void sig_exit(int sig)
+{
+	psignal(sig, "perf");
+	signal(sig, SIG_DFL);
+	raise(sig);
+}
+
 static void sig_handler(int sig __maybe_unused)
 {
 	done = true;
@@ -228,6 +235,7 @@ static int do_ftrace_live(struct perf_ftrace *ftrace)
 	signal(SIGUSR1, sig_handler);
 	signal(SIGCHLD, sig_handler);
 	signal(SIGPIPE, sig_handler);
+	signal(SIGSEGV, sig_exit);
 
 	if (setup_tracing_files(ftrace) < 0)
 		goto out_reset;
@@ -630,6 +638,7 @@ static int do_ftrace_record(struct perf_ftrace *ftrace)
 	signal(SIGINT, sig_handler);
 	signal(SIGUSR1, sig_handler);
 	signal(SIGCHLD, sig_handler);
+	signal(SIGSEGV, sig_exit);
 
 	if (setup_tracing_files(ftrace) < 0)
 		goto out_reset;
@@ -1139,6 +1148,8 @@ static int do_ftrace_show(struct perf_ftrace *ftrace)
 		},
 	};
 
+	signal(SIGSEGV, sig_exit);
+
 	canonicalize_directory_name(ftrace->dirname);
 
 	scnprintf(buf, sizeof(buf), "%s.dir/perf.header", ftrace->dirname);
@@ -1230,6 +1241,8 @@ static int do_ftrace_report(struct perf_ftrace *ftrace)
 	struct machine *machine;
 	struct dso *dso;
 
+	signal(SIGSEGV, sig_exit);
+
 	canonicalize_directory_name(ftrace->dirname);
 
 	scnprintf(buf, sizeof(buf), "%s.dir/perf.header", ftrace->dirname);
-- 
1.7.11.7

[PATCH 15/18] perf ftrace: Add --clock option

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

The --clock (-c) option is for controlling trace_clock.  Default to
'perf' if exists, or 'local'.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-ftrace.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 8fec8d6df37d..2a7acdbd6985 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -35,6 +35,7 @@ struct perf_ftrace {
 	struct perf_target target;
 	const char *tracer;
 	const char *dirname;
+	const char *clock;
 	struct pevent *pevent;
 	bool show_full_info;
 };
@@ -114,6 +115,9 @@ static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
 	if (reset_tracing_cpu() < 0)
 		return -1;
 
+	if (write_tracing_file("trace_clock", "local") < 0)
+		return -1;
+
 	return 0;
 }
 
@@ -188,6 +192,24 @@ static int reset_tracing_cpu(void)
 	return 0;
 }
 
+static int set_tracing_clock(struct perf_ftrace *ftrace)
+{
+	const char *tclock = ftrace->clock;
+
+	if (tclock == NULL)
+		tclock = "perf";
+
+	if (!write_tracing_file("trace_clock", tclock))
+		return 0;
+
+	/* exit if user specified an invalid clock */
+	if (ftrace->clock)
+		return -1;
+
+	pr_debug("'perf' clock is not supported.. falling back to 'local' clock\n");
+	return write_tracing_file("trace_clock", "local");
+}
+
 static int setup_tracing_files(struct perf_ftrace *ftrace)
 {
 	int ret = -1;
@@ -213,6 +235,11 @@ static int setup_tracing_files(struct perf_ftrace *ftrace)
 		goto out;
 	}
 
+	if (set_tracing_clock(ftrace) < 0) {
+		pr_err("failed to set trace clock\n");
+		goto out;
+	}
+
 	if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
 		pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
 		goto out;
@@ -1495,6 +1522,8 @@ __cmd_ftrace_live(struct perf_ftrace *ftrace, int argc, const char **argv)
 		    "system-wide collection from all CPUs"),
 	OPT_STRING('C', "cpu", &ftrace->target.cpu_list, "cpu",
 		    "list of cpus to monitor"),
+	OPT_STRING('c', "clock", &ftrace->clock, "clock",
+		    "clock to be used for tracer"),
 	OPT_END()
 	};
 
@@ -1537,6 +1566,8 @@ __cmd_ftrace_record(struct perf_ftrace *ftrace, int argc, const char **argv)
 		    "list of cpus to monitor"),
 	OPT_STRING('o', "output", &ftrace->dirname, "dirname",
 		   "input directory name to use (default: perf.data)"),
+	OPT_STRING('c', "clock", &ftrace->clock, "clock",
+		    "clock to be used for tracer"),
 	OPT_END()
 	};
 
-- 
1.7.11.7

[PATCH 16/18] perf ftrace: Show leaf-functions as oneliner

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

Detect leaf functions and print them in a same line.

Note that it only converts leaf-functions that doesn't have any other
records between entry and exit even in other cpus.  I left other leaf
functions as is.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-ftrace.c | 87 +++++++++++++++++++++++++++++++++++++++------
 1 file changed, 76 insertions(+), 11 deletions(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 2a7acdbd6985..94f911946ef8 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -893,34 +893,77 @@ function_handler(struct trace_seq *s, struct pevent_record *record,
 
 #define TRACE_GRAPH_INDENT  2
 
+static struct pevent_record *peek_ordered_record(struct perf_ftrace *ftrace);
+static struct pevent_record *get_ordered_record(struct perf_ftrace *ftrace);
+
+static struct event_format *fgraph_exit_event;
+
 static int
 fgraph_ent_handler(struct trace_seq *s, struct pevent_record *record,
-		   struct event_format *event, void *context __maybe_unused)
+		   struct event_format *event, void *context)
 {
 	unsigned long long depth;
 	unsigned long long val;
 	const char *func;
+	struct perf_ftrace *ftrace = context;
+	struct pevent_record *next;
+	bool is_leaf = false;
+	bool needs_free = false;
+	void *data;
+	int ret = -1;
 	int i;
 
+	/*
+	 * record->data can be invalidated after calling peek_ordered_record()
+	 * because it can unmap the current kbuffer page.  Make a copy.
+	 */
+	data = malloc(record->size);
+	if (data == NULL)
+		goto nested;
+
+	memcpy(data, record->data, record->size);
+	record->data = data;
+	needs_free = true;
+
+	/* detect leaf function and make it one-liner */
+	next = peek_ordered_record(ftrace);
+	if (next && next->cpu == record->cpu &&
+	    pevent_data_type(event->pevent, next) == fgraph_exit_event->id) {
+		is_leaf = true;
+		/* consume record */
+		get_ordered_record(ftrace);
+		free(next);
+	}
+
+nested:
 	if (pevent_get_field_val(s, event, "depth", record, &depth, 1))
-		return trace_seq_putc(s, '!');
+		goto out;
 
 	/* Function */
 	for (i = 0; i < (int)(depth * TRACE_GRAPH_INDENT); i++)
 		trace_seq_putc(s, ' ');
 
 	if (pevent_get_field_val(s, event, "func", record, &val, 1))
-		return trace_seq_putc(s, '!');
+		goto out;
 
 	func = pevent_find_function(event->pevent, val);
 
 	if (func)
-		trace_seq_printf(s, "%s() {", func);
+		trace_seq_printf(s, "%s()", func);
 	else
-		trace_seq_printf(s, "%llx() {", val);
+		trace_seq_printf(s, "%llx()", val);
 
-	trace_seq_putc(s, '\n');
-	return 0;
+	if (is_leaf)
+		trace_seq_puts(s, ";\n");
+	else
+		trace_seq_puts(s, " {\n");
+
+	ret = 0;
+out:
+	if (needs_free)
+		free(record->data);
+
+	return ret;
 }
 
 static int
@@ -1122,7 +1165,8 @@ get_ftrace_event_record(struct perf_ftrace *ftrace,
 	return fra->record;
 }
 
-static struct pevent_record *get_ordered_record(struct perf_ftrace *ftrace)
+static struct ftrace_report_arg *
+__get_ordered_record(struct perf_ftrace *ftrace)
 {
 	struct ftrace_report_arg *fra = NULL;
 	struct ftrace_report_arg *tmp;
@@ -1136,9 +1180,26 @@ static struct pevent_record *get_ordered_record(struct perf_ftrace *ftrace)
 			fra = tmp;
 		}
 	}
+	return fra;
+}
+
+static struct pevent_record *peek_ordered_record(struct perf_ftrace *ftrace)
+{
+	struct ftrace_report_arg *fra = __get_ordered_record(ftrace);
+
+	if (fra)
+		return fra->record;
+
+	return NULL;
+}
+
+static struct pevent_record *get_ordered_record(struct perf_ftrace *ftrace)
+{
+	struct ftrace_report_arg *fra = __get_ordered_record(ftrace);
 
 	if (fra) {
-		record = fra->record;
+		struct pevent_record *record = fra->record;
+
 		fra->record = NULL;
 		return record;
 	}
@@ -1194,10 +1255,10 @@ static int do_ftrace_show(struct perf_ftrace *ftrace)
 				      function_handler, NULL);
 	pevent_register_event_handler(ftrace->pevent, -1,
 				      "ftrace", "funcgraph_entry",
-				      fgraph_ent_handler, NULL);
+				      fgraph_ent_handler, ftrace);
 	pevent_register_event_handler(ftrace->pevent, -1,
 				      "ftrace", "funcgraph_exit",
-				      fgraph_ret_handler, NULL);
+				      fgraph_ret_handler, ftrace);
 
 	if (perf_session__process_events(session, &show.tool) < 0) {
 		pr_err("failed to process events\n");
@@ -1205,6 +1266,10 @@ static int do_ftrace_show(struct perf_ftrace *ftrace)
 		goto out;
 	}
 
+	fgraph_exit_event = pevent_find_event_by_name(ftrace->pevent, "ftrace",
+						     "funcgraph_exit");
+	BUG_ON(fgraph_exit_event == NULL);
+
 	trace_seq_init(&seq);
 
 	record = get_ordered_record(ftrace);
-- 
1.7.11.7

[PATCH 17/18] perf ftrace: Tidy up the function graph output of 'show' subcommand

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

Now it doesn't call pevent_print_event() but prints context info in
itself using print_graph_duration().  Make it compact by only print
cpu number and duration:

  # perf ftrace show
  ...
   10)   0.065 us |  __fsnotify_parent();
   10)            |  fsnotify() {
   10)   0.060 us |    __srcu_read_lock();
   10)   0.040 us |    __srcu_read_unlock();
   10)   0.652 us |  }
   10)   0.040 us |  fput();
   10)            |  __audit_syscall_exit() {
   10)            |    path_put() {
   10)   0.037 us |      dput();
   10)   0.032 us |      mntput();
   10)   0.563 us |    }
   10)   0.035 us |    unroll_tree_refs();
   10)   0.035 us |    kfree();
   10)   1.284 us |  }
   10)            |  __audit_syscall_entry() {
   10)   0.029 us |    current_kernel_time();
   10)   0.239 us |  }

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/builtin-ftrace.c | 35 +++++++++++++++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 94f911946ef8..6720d560d6f8 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -898,6 +898,27 @@ static struct pevent_record *get_ordered_record(struct perf_ftrace *ftrace);
 
 static struct event_format *fgraph_exit_event;
 
+static void
+print_graph_duration(struct trace_seq *s, struct event_format *event,
+		     struct pevent_record *record)
+{
+	unsigned long long duration;
+	unsigned long long rettime, calltime;
+	unsigned long usec, nsec;
+
+	if (pevent_get_field_val(s, event, "rettime", record, &rettime, 1))
+		return;
+
+	if (pevent_get_field_val(s, event, "calltime", record, &calltime, 1))
+		return;
+
+	duration = rettime - calltime;
+	usec = duration / 1000;
+	nsec = duration % 1000;
+
+	trace_seq_printf(s, "%3d) %3lu.%03lu us |  ", record->cpu, usec, nsec);
+}
+
 static int
 fgraph_ent_handler(struct trace_seq *s, struct pevent_record *record,
 		   struct event_format *event, void *context)
@@ -930,9 +951,14 @@ fgraph_ent_handler(struct trace_seq *s, struct pevent_record *record,
 	if (next && next->cpu == record->cpu &&
 	    pevent_data_type(event->pevent, next) == fgraph_exit_event->id) {
 		is_leaf = true;
+
+		print_graph_duration(s, fgraph_exit_event, next);
+
 		/* consume record */
 		get_ordered_record(ftrace);
 		free(next);
+	} else {
+		trace_seq_printf(s, "%3d) %*s |  ", record->cpu, 10, "");
 	}
 
 nested:
@@ -973,6 +999,8 @@ fgraph_ret_handler(struct trace_seq *s, struct pevent_record *record,
 	unsigned long long depth;
 	int i;
 
+	print_graph_duration(s, event, record);
+
 	if (pevent_get_field_val(s, event, "depth", record, &depth, 1))
 		return trace_seq_putc(s, '!');
 
@@ -1284,9 +1312,12 @@ static int do_ftrace_show(struct perf_ftrace *ftrace)
 			continue;
 		}
 
-		pevent_print_event(ftrace->pevent, &seq, record);
-		trace_seq_do_printf(&seq);
+		if (!strcmp(ftrace->tracer, "function_graph"))
+			pevent_event_info(&seq, event, record);
+		else
+			pevent_print_event(ftrace->pevent, &seq, record);
 
+		trace_seq_do_printf(&seq);
 		trace_seq_reset(&seq);
 
 		free(record);
-- 
1.7.11.7

[PATCH 18/18] perf ftrace: Add --filter option

[Namhyung Kim]

From: Namhyung Kim <namhyung.kim@lge.com>

The --filter (-l) option is for filtering specific functions.  If this
option is given, only these (and their children) functions will be
shown in the output.

Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/Documentation/perf-ftrace.txt |  5 +++
 tools/perf/builtin-ftrace.c              | 55 ++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+)

diff --git a/tools/perf/Documentation/perf-ftrace.txt b/tools/perf/Documentation/perf-ftrace.txt
index 841699f3924d..b0ae286d3e28 100644
--- a/tools/perf/Documentation/perf-ftrace.txt
+++ b/tools/perf/Documentation/perf-ftrace.txt
@@ -50,6 +50,11 @@ OPTIONS
 	tracer in system and outputs trace result directly from the
 	ftrace's trace_pipe.
 
+-l::
+--filter=::
+	Filter given functions to suppress others in the output.
+	Used by 'live' and 'record' subcommands only.
+
 -p::
 --pid=::
 	Record events on existing process ID (comma separated list).
diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
index 6720d560d6f8..17f37c273b1b 100644
--- a/tools/perf/builtin-ftrace.c
+++ b/tools/perf/builtin-ftrace.c
@@ -22,6 +22,7 @@
 #include "util/thread_map.h"
 #include "util/cpumap.h"
 #include "util/sort.h"
+#include "util/strlist.h"
 #include "util/trace-event.h"
 #include "../lib/traceevent/kbuffer.h"
 #include "../lib/traceevent/event-parse.h"
@@ -36,6 +37,7 @@ struct perf_ftrace {
 	const char *tracer;
 	const char *dirname;
 	const char *clock;
+	struct strlist *filter;
 	struct pevent *pevent;
 	bool show_full_info;
 };
@@ -118,6 +120,12 @@ static int reset_tracing_files(struct perf_ftrace *ftrace __maybe_unused)
 	if (write_tracing_file("trace_clock", "local") < 0)
 		return -1;
 
+	if (write_tracing_file("set_ftrace_filter", " ") < 0)
+		return -1;
+
+	if (write_tracing_file("set_graph_function", " ") < 0)
+		return -1;
+
 	return 0;
 }
 
@@ -210,6 +218,28 @@ static int set_tracing_clock(struct perf_ftrace *ftrace)
 	return write_tracing_file("trace_clock", "local");
 }
 
+static int set_tracing_filter(struct perf_ftrace *ftrace)
+{
+	const char *filter_file;
+	struct str_node *func;
+
+	if (ftrace->filter == NULL)
+		return 0;
+
+	if (!strcmp(ftrace->tracer, "function_graph"))
+		filter_file = "set_graph_function";
+	else if (!strcmp(ftrace->tracer, "function"))
+		filter_file = "set_ftrace_filter";
+	else
+		return 0;
+
+	strlist__for_each(func, ftrace->filter) {
+		if (append_tracing_file(filter_file, func->s) < 0)
+			return -1;
+	}
+	return 0;
+}
+
 static int setup_tracing_files(struct perf_ftrace *ftrace)
 {
 	int ret = -1;
@@ -240,6 +270,11 @@ static int setup_tracing_files(struct perf_ftrace *ftrace)
 		goto out;
 	}
 
+	if (set_tracing_filter(ftrace) < 0) {
+		pr_err("failed to set ftrace filter\n");
+		goto out;
+	}
+
 	if (write_tracing_file("current_tracer", ftrace->tracer) < 0) {
 		pr_err("failed to set current_tracer to %s\n", ftrace->tracer);
 		goto out;
@@ -1596,6 +1631,22 @@ static void ftrace_teardown(struct perf_ftrace *ftrace)
 {
 	perf_evlist__delete_maps(ftrace->evlist);
 	perf_evlist__delete(ftrace->evlist);
+	strlist__delete(ftrace->filter);
+}
+
+static int function_filters(const struct option *opt, const char *str,
+			    int unset __maybe_unused)
+{
+	struct perf_ftrace *ftrace = opt->value;
+
+	if (ftrace->filter == NULL) {
+		ftrace->filter = strlist__new(true, NULL);
+		if (ftrace->filter == NULL)
+			return -ENOMEM;
+	}
+
+	strlist__parse_list(ftrace->filter, str);
+	return 0;
 }
 
 static int
@@ -1610,6 +1661,8 @@ __cmd_ftrace_live(struct perf_ftrace *ftrace, int argc, const char **argv)
 	const struct option live_options[] = {
 	OPT_STRING('t', "tracer", &ftrace->tracer, "tracer",
 		   "tracer to use: function_graph or function"),
+	OPT_CALLBACK('l', "filter", ftrace, "function[,function,...]",
+		     "show only these functions in the trace", function_filters),
 	OPT_STRING('p', "pid", &ftrace->target.pid, "pid",
 		   "trace on existing process id"),
 	OPT_INCR('v', "verbose", &verbose,
@@ -1652,6 +1705,8 @@ __cmd_ftrace_record(struct perf_ftrace *ftrace, int argc, const char **argv)
 	const struct option record_options[] = {
 	OPT_STRING('t', "tracer", &ftrace->tracer, "tracer",
 		   "tracer to use: function_graph or function"),
+	OPT_CALLBACK('l', "filter", ftrace, "function[,function,...]",
+		     "show only these functions in the trace", function_filters),
 	OPT_STRING('p', "pid", &ftrace->target.pid, "pid",
 		   "trace on existing process id"),
 	OPT_INCR('v', "verbose", &verbose,
-- 
1.7.11.7