From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755698Ab1GLVQo (ORCPT ); Tue, 12 Jul 2011 17:16:44 -0400 Received: from smtp-out.google.com ([74.125.121.67]:16800 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755648Ab1GLVQm (ORCPT ); Tue, 12 Jul 2011 17:16:42 -0400 From: Sonny Rao To: acme@redhat.com Cc: anton@samba.org, rostedt@goodmis.org, Sonny Rao , Peter Zijlstra , Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org Subject: [PATCH] [RFC] perf: robustify proc and debugfs file recording Date: Tue, 12 Jul 2011 14:15:48 -0700 Message-Id: <1310505348-20163-1-git-send-email-sonnyrao@chromium.org> X-Mailer: git-send-email 1.7.3.1 X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org While attempting to create a timechart of boot up I found perf didn't tolerate modules being loaded/unloaded. This patch fixes this by reading the file once and then writing the size read at the correct point in the file. It also simplifies the code somewhat. Signed-off-by: Sonny Rao --- tools/perf/util/trace-event-info.c | 114 +++++++++--------------------------- 1 files changed, 27 insertions(+), 87 deletions(-) diff --git a/tools/perf/util/trace-event-info.c b/tools/perf/util/trace-event-info.c index 35729f4..5a7e562 100644 --- a/tools/perf/util/trace-event-info.c +++ b/tools/perf/util/trace-event-info.c @@ -183,106 +183,60 @@ int bigendian(void) return *ptr == 0x01020304; } -static unsigned long long copy_file_fd(int fd) +/* unfortunately, you can not stat debugfs or proc files for size */ +static void record_file(const char *file, size_t hdr_sz) { unsigned long long size = 0; - char buf[BUFSIZ]; - int r; - - do { - r = read(fd, buf, BUFSIZ); - if (r > 0) { - size += r; - write_or_die(buf, r); - } - } while (r > 0); - - return size; -} - -static unsigned long long copy_file(const char *file) -{ - unsigned long long size = 0; - int fd; + char buf[BUFSIZ], *sizep; + off_t hdr_pos = lseek(output_fd, 0, SEEK_CUR); + int r, fd; fd = open(file, O_RDONLY); if (fd < 0) die("Can't read '%s'", file); - size = copy_file_fd(fd); - close(fd); - return size; -} - -static unsigned long get_size_fd(int fd) -{ - unsigned long long size = 0; - char buf[BUFSIZ]; - int r; + /* put in zeros for file size, then fill true size later */ + write_or_die(&size, hdr_sz); do { r = read(fd, buf, BUFSIZ); - if (r > 0) + if (r > 0) { size += r; + write_or_die(buf, r); + } } while (r > 0); - - lseek(fd, 0, SEEK_SET); - - return size; -} - -static unsigned long get_size(const char *file) -{ - unsigned long long size = 0; - int fd; - - fd = open(file, O_RDONLY); - if (fd < 0) - die("Can't read '%s'", file); - size = get_size_fd(fd); close(fd); - return size; + /* ugh, handle big-endian hdr_size == 4 */ + sizep = (char*)&size; + if (bigendian()) + sizep += sizeof(u64) - hdr_sz; + + if (pwrite(output_fd, &size, hdr_sz, hdr_pos) < 0) + die("writing to %s", output_file); } static void read_header_files(void) { unsigned long long size, check_size; char *path; - int fd; + struct stat st; path = get_tracing_file("events/header_page"); - fd = open(path, O_RDONLY); - if (fd < 0) + if (stat(path, &st) < 0) die("can't read '%s'", path); - /* unfortunately, you can not stat debugfs files for size */ - size = get_size_fd(fd); - write_or_die("header_page", 12); - write_or_die(&size, 8); - check_size = copy_file_fd(fd); - close(fd); - - if (size != check_size) - die("wrong size for '%s' size=%lld read=%lld", - path, size, check_size); + record_file(path, 8); put_tracing_file(path); path = get_tracing_file("events/header_event"); - fd = open(path, O_RDONLY); - if (fd < 0) + if (stat(path, &st) < 0) die("can't read '%s'", path); - size = get_size_fd(fd); - write_or_die("header_event", 13); - write_or_die(&size, 8); - check_size = copy_file_fd(fd); - if (size != check_size) - die("wrong size for '%s'", path); + record_file(path, 8); put_tracing_file(path); - close(fd); } static bool name_in_tp_list(char *sys, struct tracepoint_path *tps) @@ -338,14 +292,8 @@ static void copy_event_system(const char *sys, struct tracepoint_path *tps) sprintf(format, "%s/%s/format", sys, dent->d_name); ret = stat(format, &st); - if (ret >= 0) { - /* unfortunately, you can not stat debugfs files for size */ - size = get_size(format); - write_or_die(&size, 8); - check_size = copy_file(format); - if (size != check_size) - die("error in size of file '%s'", format); - } + if (ret >= 0) + record_file(format, 8); free(format); } @@ -438,12 +386,7 @@ static void read_proc_kallsyms(void) write_or_die(&size, 4); return; } - size = get_size(path); - write_or_die(&size, 4); - check_size = copy_file(path); - if (size != check_size) - die("error in size of file '%s'", path); - + record_file(path, 4); } static void read_ftrace_printk(void) @@ -461,11 +404,8 @@ static void read_ftrace_printk(void) write_or_die(&size, 4); goto out; } - size = get_size(path); - write_or_die(&size, 4); - check_size = copy_file(path); - if (size != check_size) - die("error in size of file '%s'", path); + record_file(path, 4); + out: put_tracing_file(path); } -- 1.7.3.1