[PATCHSET 0/5] perf tools: Add support log window on TUI (v4)

[PATCHSET 0/5] perf tools: Add support log window on TUI (v4)

[Namhyung Kim]

Hello,

This is a new attempt to add a log window support on TUI browser.  The
header window support was already merged to acme/perf/core.

 * changes in v3)
  - use tmpfile(3) instead of mkstemp (David)
  - check NULL fp before use (David)
  - rename functions to follow the 'class__method' convention (Arnaldo)
  - restore original position when write failed (David)

You can get it from the 'perf/tui-v4' branch in my tree:

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

Any comments are welcome, thanks
Namhyung


Namhyung Kim (5):
  perf tools: Introduce struct perf_log
  perf tools: Save message when pr_*() was called
  perf ui/tui: Implement log window
  perf ui/tui: Filter messages in log window
  perf ui/tui: Remember last log line for filtering

 tools/perf/Makefile.perf       |   2 +
 tools/perf/perf.c              |   5 +
 tools/perf/ui/browser.h        |   1 +
 tools/perf/ui/browsers/hists.c |   5 +
 tools/perf/ui/browsers/log.c   | 235 +++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/debug.c        |   6 ++
 tools/perf/util/debug.h        |  16 +++
 tools/perf/util/log.c          | 117 ++++++++++++++++++++
 8 files changed, 387 insertions(+)
 create mode 100644 tools/perf/ui/browsers/log.c
 create mode 100644 tools/perf/util/log.c

-- 
1.7.11.7

[PATCH 1/5] perf tools: Introduce struct perf_log

[Namhyung Kim]

Add new functions to save error messages in a temp file.  It'll be
used by some UI front-ends to see the messages.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/Makefile.perf |   1 +
 tools/perf/perf.c        |   5 +++
 tools/perf/util/debug.h  |  15 +++++++
 tools/perf/util/log.c    | 115 +++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 136 insertions(+)
 create mode 100644 tools/perf/util/log.c

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 87d7726cee2d..2b5252f09c04 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -372,6 +372,7 @@ LIB_OBJS += $(OUTPUT)util/stat.o
 LIB_OBJS += $(OUTPUT)util/record.o
 LIB_OBJS += $(OUTPUT)util/srcline.o
 LIB_OBJS += $(OUTPUT)util/data.o
+LIB_OBJS += $(OUTPUT)util/log.o
 
 LIB_OBJS += $(OUTPUT)ui/setup.o
 LIB_OBJS += $(OUTPUT)ui/helpline.o
diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 431798a4110d..f7c806d264a2 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -10,6 +10,7 @@
 
 #include "util/exec_cmd.h"
 #include "util/cache.h"
+#include "util/debug.h"
 #include "util/quote.h"
 #include "util/run-command.h"
 #include "util/parse-events.h"
@@ -524,6 +525,9 @@ int main(int argc, const char **argv)
 	 */
 	pthread__block_sigwinch();
 
+	if (perf_log__init() < 0)
+		fprintf(stderr, "Failed to init temporary log file.. ignoring\n");
+
 	while (1) {
 		static int done_help;
 		int was_alias = run_argv(&argc, &argv);
@@ -547,5 +551,6 @@ int main(int argc, const char **argv)
 	fprintf(stderr, "Failed to run command '%s': %s\n",
 		cmd, strerror(errno));
 out:
+	perf_log__exit();
 	return 1;
 }
diff --git a/tools/perf/util/debug.h b/tools/perf/util/debug.h
index 443694c36b03..2d69e9fa6499 100644
--- a/tools/perf/util/debug.h
+++ b/tools/perf/util/debug.h
@@ -19,4 +19,19 @@ int ui__warning(const char *format, ...) __attribute__((format(printf, 1, 2)));
 
 void pr_stat(const char *fmt, ...);
 
+struct perf_log {
+	FILE *fp;
+	off_t *linemap;
+	u32 lines;
+	u32 nr_alloc;
+	bool seen_newline;
+};
+
+extern struct perf_log perf_log;
+
+int perf_log__init(void);
+int perf_log__exit(void);
+void perf_log__add(const char *msg);
+void perf_log__addv(const char *fmt, va_list ap);
+
 #endif	/* __PERF_DEBUG_H */
diff --git a/tools/perf/util/log.c b/tools/perf/util/log.c
new file mode 100644
index 000000000000..cb94417da435
--- /dev/null
+++ b/tools/perf/util/log.c
@@ -0,0 +1,115 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "util/debug.h"
+
+#define LINEMAP_GROW  128
+
+struct perf_log perf_log = {
+	.seen_newline = true,
+};
+
+int perf_log__init(void)
+{
+	FILE *fp = tmpfile();
+	if (fp == NULL)
+		return -1;
+
+	perf_log.fp = fp;
+
+	return 0;
+}
+
+int perf_log__exit(void)
+{
+	FILE *fp = perf_log.fp;
+	if (fp)
+		fclose(fp);
+
+	free(perf_log.linemap);
+
+	perf_log.fp = NULL;
+	perf_log.linemap = NULL;
+	return 0;
+}
+
+static int grow_linemap(struct perf_log *log)
+{
+	off_t *newmap;
+	int newsize = log->nr_alloc + LINEMAP_GROW;
+
+	newmap = realloc(log->linemap, newsize * sizeof(*log->linemap));
+	if (newmap == NULL)
+		return -1;
+
+	log->nr_alloc = newsize;
+	log->linemap = newmap;
+	return 0;
+}
+
+static int __add_to_linemap(struct perf_log *log, off_t idx)
+{
+	if (log->lines == log->nr_alloc)
+		if (grow_linemap(log) < 0)
+			return -1;
+
+	log->linemap[log->lines++] = idx;
+	return 0;
+}
+
+static void add_to_linemap(struct perf_log *log, const char *msg, off_t base)
+{
+	const char *pos;
+
+	if (strlen(msg) == 0)
+		return;
+
+	if (log->seen_newline) {
+		if (__add_to_linemap(log, base) < 0)
+			return;
+	}
+
+	if ((pos = strchr(msg, '\n')) != NULL) {
+		log->seen_newline = true;
+		pos++;
+		add_to_linemap(log, pos, base + (pos - msg));
+	} else {
+		log->seen_newline = false;
+	}
+}
+
+void perf_log__add(const char *msg)
+{
+	FILE *fp = perf_log.fp;
+	off_t offset;
+	u32 saved_lines;
+	size_t msglen;
+
+	if (fp == NULL)
+		return;
+
+	pthread_mutex_lock(&ui__lock);
+
+	offset = ftello(fp);
+	saved_lines = perf_log.lines;
+	msglen = strlen(msg);
+
+	add_to_linemap(&perf_log, msg, offset);
+
+	if (fwrite(msg, 1, msglen, fp) != msglen) {
+		/* restore original offset */
+		fseeko(fp, offset, SEEK_SET);
+		perf_log.lines = saved_lines;
+	}
+	pthread_mutex_unlock(&ui__lock);
+}
+
+void perf_log__addv(const char *fmt, va_list ap)
+{
+	char buf[4096];
+
+	if (perf_log.fp == NULL)
+		return;
+
+	vsnprintf(buf, sizeof(buf), fmt, ap);
+	perf_log__add(buf);
+}
-- 
1.7.11.7

[PATCH 2/5] perf tools: Save message when pr_*() was called

[Namhyung Kim]

The message will be saved in a temp file so that it can be shown at a
UI dialog at any time.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/util/debug.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
index 299b55586502..801cdf205d3e 100644
--- a/tools/perf/util/debug.c
+++ b/tools/perf/util/debug.c
@@ -19,12 +19,18 @@ bool dump_trace = false, quiet = false;
 static int _eprintf(int level, const char *fmt, va_list args)
 {
 	int ret = 0;
+	va_list ap;
 
 	if (verbose >= level) {
+		va_copy(ap, args);
+
 		if (use_browser >= 1)
 			ui_helpline__vshow(fmt, args);
 		else
 			ret = vfprintf(stderr, fmt, args);
+
+		perf_log__addv(fmt, ap);
+		va_end(ap);
 	}
 
 	return ret;
-- 
1.7.11.7

[PATCH 3/5] perf ui/tui: Implement log window

[Namhyung Kim]

Implement a simple, full-screen log window which shows error messages
saved so far.  Press 'l' (lower-case 'L') key to display the log
window.  It'll be used usually with -v option.

Protect updating log by ui__lock to prevent the linemap reallocation
during log window refresh (it led to a segfault) and add
linemap_changed member to perf_log in order to detect the change.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/Makefile.perf       |   1 +
 tools/perf/ui/browser.h        |   1 +
 tools/perf/ui/browsers/hists.c |   5 ++
 tools/perf/ui/browsers/log.c   | 132 +++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/debug.h        |   1 +
 tools/perf/util/log.c          |   2 +
 6 files changed, 142 insertions(+)
 create mode 100644 tools/perf/ui/browsers/log.c

diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 2b5252f09c04..51d87a25d17d 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -491,6 +491,7 @@ ifndef NO_SLANG
   LIB_OBJS += $(OUTPUT)ui/browsers/map.o
   LIB_OBJS += $(OUTPUT)ui/browsers/scripts.o
   LIB_OBJS += $(OUTPUT)ui/browsers/header.o
+  LIB_OBJS += $(OUTPUT)ui/browsers/log.o
   LIB_OBJS += $(OUTPUT)ui/tui/setup.o
   LIB_OBJS += $(OUTPUT)ui/tui/util.o
   LIB_OBJS += $(OUTPUT)ui/tui/helpline.o
diff --git a/tools/perf/ui/browser.h b/tools/perf/ui/browser.h
index 118cca29dd26..1f676c8ec4f3 100644
--- a/tools/perf/ui/browser.h
+++ b/tools/perf/ui/browser.h
@@ -61,6 +61,7 @@ int ui_browser__input_window(const char *title, const char *text, char *input,
 			     const char *exit_msg, int delay_sec);
 struct perf_session_env;
 int tui__header_window(struct perf_session_env *env);
+int tui__log_window(void);
 
 void ui_browser__argv_seek(struct ui_browser *browser, off_t offset, int whence);
 unsigned int ui_browser__argv_refresh(struct ui_browser *browser);
diff --git a/tools/perf/ui/browsers/hists.c b/tools/perf/ui/browsers/hists.c
index b720b92eba6e..e0ab399d431d 100644
--- a/tools/perf/ui/browsers/hists.c
+++ b/tools/perf/ui/browsers/hists.c
@@ -1416,6 +1416,7 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
 	/* help messages are sorted by lexical order of the hotkey */
 	const char report_help[] = HIST_BROWSER_HELP_COMMON
 	"i             Show header information\n"
+	"l             Show log messages\n"
 	"P             Print histograms to perf.hist.N\n"
 	"r             Run available scripts\n"
 	"s             Switch to another data file in PWD\n"
@@ -1423,6 +1424,7 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
 	"V             Verbose (DSO names in callchains, etc)\n"
 	"/             Filter symbol by name";
 	const char top_help[] = HIST_BROWSER_HELP_COMMON
+	"l             Show log messages\n"
 	"P             Print histograms to perf.hist.N\n"
 	"t             Zoom into current Thread\n"
 	"V             Verbose (DSO names in callchains, etc)\n"
@@ -1517,6 +1519,9 @@ static int perf_evsel__hists_browse(struct perf_evsel *evsel, int nr_events,
 			if (env->arch)
 				tui__header_window(env);
 			continue;
+		case 'l':
+			tui__log_window();
+			continue;
 		case K_F1:
 		case 'h':
 		case '?':
diff --git a/tools/perf/ui/browsers/log.c b/tools/perf/ui/browsers/log.c
new file mode 100644
index 000000000000..c64aeb8f9aac
--- /dev/null
+++ b/tools/perf/ui/browsers/log.c
@@ -0,0 +1,132 @@
+#include <stdio.h>
+
+#include "perf.h"
+#include "util/util.h"
+#include "util/cache.h"
+#include "util/debug.h"
+#include "ui/ui.h"
+#include "ui/util.h"
+#include "ui/browser.h"
+#include "ui/libslang.h"
+#include "ui/keysyms.h"
+
+static void ui_browser__file_seek(struct ui_browser *browser __maybe_unused,
+				  off_t offset __maybe_unused,
+				  int whence __maybe_unused)
+{
+	/* do nothing */
+}
+
+static void ui_browser__file_write(struct ui_browser *browser,
+				   void *entry, int row)
+{
+	char buf[1024];
+	char empty[] = " ";
+	FILE *fp = perf_log.fp;
+	bool current_entry = ui_browser__is_current_entry(browser, row);
+	off_t *linemap = perf_log.linemap;
+	unsigned int idx = *(unsigned int *)entry;
+	unsigned long offset = (unsigned long)browser->priv;
+
+	fseek(fp, linemap[idx], SEEK_SET);
+	if (fgets(buf, sizeof(buf), fp) == NULL)
+		return;
+
+	ui_browser__set_color(browser, current_entry ? HE_COLORSET_SELECTED :
+						       HE_COLORSET_NORMAL);
+
+	if (offset < strlen(buf))
+		slsmg_write_nstring(&buf[offset], browser->width);
+	else
+		slsmg_write_nstring(empty, browser->width);
+}
+
+static unsigned int ui_browser__file_refresh(struct ui_browser *browser)
+{
+	unsigned int row = 0;
+	unsigned int idx = browser->top_idx;
+	fpos_t pos;
+
+	fgetpos(perf_log.fp, &pos);
+
+	if (perf_log.linemap_changed) {
+		/* update log window with new linemap */
+		browser->entries = perf_log.linemap;
+		browser->nr_entries = perf_log.lines;
+		perf_log.linemap_changed = false;
+	}
+
+	while (idx < browser->nr_entries) {
+		ui_browser__gotorc(browser, row, 0);
+		browser->write(browser, &idx, row);
+		if (++row == browser->height)
+			break;
+
+		++idx;
+	}
+
+	fsetpos(perf_log.fp, &pos);
+	return row;
+}
+
+static int log_menu__run(struct ui_browser *menu)
+{
+	int key;
+	unsigned long offset;
+	const char help[] =
+	"h/?/F1        Show this window\n"
+	"UP/DOWN/PGUP\n"
+	"PGDN/SPACE\n"
+	"LEFT/RIGHT    Navigate\n"
+	"q/ESC/CTRL+C  Exit browser";
+
+	if (ui_browser__show(menu, "Log messages", "Press 'q' to exit") < 0)
+		return -1;
+
+	while (1) {
+		key = ui_browser__run(menu, 0);
+
+		switch (key) {
+		case K_RIGHT:
+			offset = (unsigned long)menu->priv;
+			offset += 10;
+			menu->priv = (void *)offset;
+			continue;
+		case K_LEFT:
+			offset = (unsigned long)menu->priv;
+			if (offset >= 10)
+				offset -= 10;
+			menu->priv = (void *)offset;
+			continue;
+		case K_F1:
+		case 'h':
+		case '?':
+			ui_browser__help_window(menu, help);
+			continue;
+		case K_ESC:
+		case 'q':
+		case CTRL('c'):
+			key = -1;
+			break;
+		default:
+			continue;
+		}
+
+		break;
+	}
+
+	ui_browser__hide(menu);
+	return key;
+}
+
+int tui__log_window(void)
+{
+	struct ui_browser log_menu = {
+		.refresh    = ui_browser__file_refresh,
+		.seek	    = ui_browser__file_seek,
+		.write	    = ui_browser__file_write,
+		.nr_entries = perf_log.lines,
+	};
+
+	return log_menu__run(&log_menu);
+}
diff --git a/tools/perf/util/debug.h b/tools/perf/util/debug.h
index 2d69e9fa6499..469abfcdc7c0 100644
--- a/tools/perf/util/debug.h
+++ b/tools/perf/util/debug.h
@@ -25,6 +25,7 @@ struct perf_log {
 	u32 lines;
 	u32 nr_alloc;
 	bool seen_newline;
+	bool linemap_changed;
 };
 
 extern struct perf_log perf_log;
diff --git a/tools/perf/util/log.c b/tools/perf/util/log.c
index cb94417da435..4b05345c35c7 100644
--- a/tools/perf/util/log.c
+++ b/tools/perf/util/log.c
@@ -99,6 +99,8 @@ void perf_log__add(const char *msg)
 		/* restore original offset */
 		fseeko(fp, offset, SEEK_SET);
 		perf_log.lines = saved_lines;
+	} else {
+		perf_log.linemap_changed = true;
 	}
 	pthread_mutex_unlock(&ui__lock);
 }
-- 
1.7.11.7

[PATCH 4/5] perf ui/tui: Filter messages in log window

[Namhyung Kim]

Press '/' key to input filter string like main hist browser does.

Requested-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/ui/browsers/log.c | 117 +++++++++++++++++++++++++++++++++++++------
 1 file changed, 103 insertions(+), 14 deletions(-)

diff --git a/tools/perf/ui/browsers/log.c b/tools/perf/ui/browsers/log.c
index c64aeb8f9aac..62343e0578bb 100644
--- a/tools/perf/ui/browsers/log.c
+++ b/tools/perf/ui/browsers/log.c
@@ -10,6 +10,14 @@
 #include "ui/libslang.h"
 #include "ui/keysyms.h"
 
+struct log_browser_data {
+	unsigned long offset;
+	u32 alloc;
+	char filter[64];
+};
+
+static void __log_menu__filter(struct ui_browser *menu, char *filter);
+
 static void ui_browser__file_seek(struct ui_browser *browser __maybe_unused,
 				  off_t offset __maybe_unused,
 				  int whence __maybe_unused)
@@ -23,10 +31,11 @@ static void ui_browser__file_write(struct ui_browser *browser,
 	char buf[1024];
 	char empty[] = " ";
 	FILE *fp = perf_log.fp;
+	struct log_browser_data *lbd = browser->priv;
 	bool current_entry = ui_browser__is_current_entry(browser, row);
-	off_t *linemap = perf_log.linemap;
+	off_t *linemap = browser->entries;
 	unsigned int idx = *(unsigned int *)entry;
-	unsigned long offset = (unsigned long)browser->priv;
+	unsigned long offset = lbd->offset;
 
 	fseek(fp, linemap[idx], SEEK_SET);
 	if (fgets(buf, sizeof(buf), fp) == NULL)
@@ -45,14 +54,14 @@ static unsigned int ui_browser__file_refresh(struct ui_browser *browser)
 {
 	unsigned int row = 0;
 	unsigned int idx = browser->top_idx;
+	struct log_browser_data *lbd = browser->priv;
 	fpos_t pos;
 
 	fgetpos(perf_log.fp, &pos);
 
 	if (perf_log.linemap_changed) {
 		/* update log window with new linemap */
-		browser->entries = perf_log.linemap;
-		browser->nr_entries = perf_log.lines;
+		__log_menu__filter(browser, lbd->filter);
 		perf_log.linemap_changed = false;
 	}
 
@@ -69,16 +78,81 @@ static unsigned int ui_browser__file_refresh(struct ui_browser *browser)
 	return row;
 }
 
+static void __log_menu__filter(struct ui_browser *menu, char *filter)
+{
+	char buf[1024];
+	struct log_browser_data *lbd = menu->priv;
+	off_t *linemap = NULL;
+	u32 lines = 0;
+	u32 alloc = 0;
+	u32 i;
+
+	if (*filter == '\0') {
+		linemap = perf_log.linemap;
+		lines = perf_log.lines;
+		goto out;
+	}
+
+	for (i = 0; i < perf_log.lines; i++) {
+		fseek(perf_log.fp, perf_log.linemap[i], SEEK_SET);
+		if (fgets(buf, sizeof(buf), perf_log.fp) == NULL)
+			goto error;
+
+		if (strstr(buf, filter) == NULL)
+			continue;
+
+		if (lines == alloc) {
+			off_t *map;
+
+			map = realloc(linemap, (alloc + 128) * sizeof(*map));
+			if (map == NULL)
+				goto error;
+
+			linemap = map;
+			alloc += 128;
+		}
+
+		linemap[lines++] = perf_log.linemap[i];
+	}
+
+out:
+	if (lbd->alloc) {
+		BUG_ON(menu->entries == perf_log.linemap);
+		free(menu->entries);
+	}
+	lbd->alloc = alloc;
+
+	menu->entries = linemap;
+	ui_browser__update_nr_entries(menu, lines);
+	return;
+
+error:
+	free(linemap);
+}
+
+static void log_menu__filter(struct ui_browser *menu, char *filter)
+{
+	fpos_t pos;
+
+	pthread_mutex_lock(&ui__lock);
+	fgetpos(perf_log.fp, &pos);
+	__log_menu__filter(menu, filter);
+	fsetpos(perf_log.fp, &pos);
+	perf_log.linemap_changed = false;
+	pthread_mutex_unlock(&ui__lock);
+}
+
 static int log_menu__run(struct ui_browser *menu)
 {
 	int key;
-	unsigned long offset;
+	struct log_browser_data *lbd = menu->priv;
 	const char help[] =
 	"h/?/F1        Show this window\n"
 	"UP/DOWN/PGUP\n"
 	"PGDN/SPACE\n"
 	"LEFT/RIGHT    Navigate\n"
-	"q/ESC/CTRL+C  Exit browser";
+	"q/ESC/CTRL+C  Exit browser\n\n"
+	"/             Filter log message";
 
 	if (ui_browser__show(menu, "Log messages", "Press 'q' to exit") < 0)
 		return -1;
@@ -88,21 +162,25 @@ static int log_menu__run(struct ui_browser *menu)
 
 		switch (key) {
 		case K_RIGHT:
-			offset = (unsigned long)menu->priv;
-			offset += 10;
-			menu->priv = (void *)offset;
+			lbd->offset += 10;
 			continue;
 		case K_LEFT:
-			offset = (unsigned long)menu->priv;
-			if (offset >= 10)
-				offset -= 10;
-			menu->priv = (void *)offset;
+			if (lbd->offset >= 10)
+				lbd->offset -= 10;
 			continue;
 		case K_F1:
 		case 'h':
 		case '?':
 			ui_browser__help_window(menu, help);
 			continue;
+		case '/':
+			if (ui_browser__input_window("Symbol to filter",
+					"Please enter the name of symbol you want to see",
+					lbd->filter, "ENTER: OK, ESC: Cancel",
+					0) == K_ENTER) {
+				log_menu__filter(menu, lbd->filter);
+			}
+			continue;
 		case K_ESC:
 		case 'q':
 		case CTRL('c'):
@@ -121,12 +199,23 @@ static int log_menu__run(struct ui_browser *menu)
 
 int tui__log_window(void)
 {
+	struct log_browser_data lbd = {
+		.filter	    = "",
+	};
 	struct ui_browser log_menu = {
 		.refresh    = ui_browser__file_refresh,
 		.seek	    = ui_browser__file_seek,
 		.write	    = ui_browser__file_write,
+		.entries    = perf_log.linemap,
 		.nr_entries = perf_log.lines,
+		.priv	    = &lbd,
 	};
+	int key;
+
+	key = log_menu__run(&log_menu);
 
-	return log_menu__run(&log_menu);
+	if (lbd.alloc)
+		free(log_menu.entries);
+
+	return key;
 }
-- 
1.7.11.7

[PATCH 5/5] perf ui/tui: Remember last log line for filtering

[Namhyung Kim]

When updating log window with filter string, no need to search all
logs everytime.  Just save the last offset and update from there.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
 tools/perf/ui/browsers/log.c | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/tools/perf/ui/browsers/log.c b/tools/perf/ui/browsers/log.c
index 62343e0578bb..828b98522a48 100644
--- a/tools/perf/ui/browsers/log.c
+++ b/tools/perf/ui/browsers/log.c
@@ -13,10 +13,11 @@
 struct log_browser_data {
 	unsigned long offset;
 	u32 alloc;
+	u32 last_log_line;
 	char filter[64];
 };
 
-static void __log_menu__filter(struct ui_browser *menu, char *filter);
+static void __log_menu__filter(struct ui_browser *menu, char *filter, bool update);
 
 static void ui_browser__file_seek(struct ui_browser *browser __maybe_unused,
 				  off_t offset __maybe_unused,
@@ -61,7 +62,7 @@ static unsigned int ui_browser__file_refresh(struct ui_browser *browser)
 
 	if (perf_log.linemap_changed) {
 		/* update log window with new linemap */
-		__log_menu__filter(browser, lbd->filter);
+		__log_menu__filter(browser, lbd->filter, true);
 		perf_log.linemap_changed = false;
 	}
 
@@ -78,14 +79,15 @@ static unsigned int ui_browser__file_refresh(struct ui_browser *browser)
 	return row;
 }
 
-static void __log_menu__filter(struct ui_browser *menu, char *filter)
+static void __log_menu__filter(struct ui_browser *menu, char *filter, bool update)
 {
 	char buf[1024];
 	struct log_browser_data *lbd = menu->priv;
 	off_t *linemap = NULL;
 	u32 lines = 0;
 	u32 alloc = 0;
-	u32 i;
+	u32 last = 0;
+	u32 i = 0;
 
 	if (*filter == '\0') {
 		linemap = perf_log.linemap;
@@ -93,7 +95,14 @@ static void __log_menu__filter(struct ui_browser *menu, char *filter)
 		goto out;
 	}
 
-	for (i = 0; i < perf_log.lines; i++) {
+	if (update) {
+		linemap = menu->entries;
+		lines = menu->nr_entries;
+		alloc = lbd->alloc;
+		last = lbd->last_log_line;
+	}
+
+	for (i = last; i < perf_log.lines; i++) {
 		fseek(perf_log.fp, perf_log.linemap[i], SEEK_SET);
 		if (fgets(buf, sizeof(buf), perf_log.fp) == NULL)
 			goto error;
@@ -116,11 +125,16 @@ static void __log_menu__filter(struct ui_browser *menu, char *filter)
 	}
 
 out:
-	if (lbd->alloc) {
+	if (!update && lbd->alloc) {
 		BUG_ON(menu->entries == perf_log.linemap);
 		free(menu->entries);
 	}
+
 	lbd->alloc = alloc;
+	lbd->last_log_line = i;
+
+	if (!update)
+		ui_browser__reset_index(menu);
 
 	menu->entries = linemap;
 	ui_browser__update_nr_entries(menu, lines);
@@ -136,7 +150,7 @@ static void log_menu__filter(struct ui_browser *menu, char *filter)
 
 	pthread_mutex_lock(&ui__lock);
 	fgetpos(perf_log.fp, &pos);
-	__log_menu__filter(menu, filter);
+	__log_menu__filter(menu, filter, false);
 	fsetpos(perf_log.fp, &pos);
 	perf_log.linemap_changed = false;
 	pthread_mutex_unlock(&ui__lock);
-- 
1.7.11.7