From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755112Ab0CVQKu (ORCPT ); Mon, 22 Mar 2010 12:10:50 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:56550 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754810Ab0CVQKk (ORCPT ); Mon, 22 Mar 2010 12:10:40 -0400 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Arnaldo Carvalho de Melo , =?utf-8?q?Fr=C3=A9d=C3=A9ric=20Weisbecker?= , Mike Galbraith , Peter Zijlstra , Paul Mackerras Subject: [PATCH 4/5] perf stat: Better report failure to collect system wide stats Date: Mon, 22 Mar 2010 13:10:28 -0300 Message-Id: <1269274229-20442-4-git-send-email-acme@infradead.org> X-Mailer: git-send-email 1.6.2.5 In-Reply-To: <1269274229-20442-1-git-send-email-acme@infradead.org> References: <1269274229-20442-1-git-send-email-acme@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnaldo Carvalho de Melo Before: [acme@doppio linux-2.6-tip]$ perf stat -a sleep 1s Performance counter stats for 'sleep 1s': task-clock-msecs context-switches CPU-migrations page-faults cycles instructions branches branch-misses cache-references cache-misses 1.016998463 seconds time elapsed [acme@doppio linux-2.6-tip]$ Now: [acme@doppio linux-2.6-tip]$ perf stat -a sleep 1s No permission to collect system-wide stats. Consider tweaking /proc/sys/kernel/perf_event_paranoid. [acme@doppio linux-2.6-tip]$ Reported-by: Ingo Molnar Cc: Frédéric Weisbecker Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Paul Mackerras Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-stat.c | 39 ++++++++++++++++++++++++++++----------- 1 files changed, 28 insertions(+), 11 deletions(-) diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index c92f90f..1036ca7 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -144,10 +144,11 @@ struct stats runtime_branches_stats; #define ERR_PERF_OPEN \ "Error: counter %d, sys_perf_event_open() syscall returned with %d (%s)\n" -static void create_perf_stat_counter(int counter) +static int create_perf_stat_counter(int counter) { struct perf_event_attr *attr = attrs + counter; int thread; + int ncreated = 0; if (scale) attr->read_format = PERF_FORMAT_TOTAL_TIME_ENABLED | @@ -159,9 +160,11 @@ static void create_perf_stat_counter(int counter) for (cpu = 0; cpu < nr_cpus; cpu++) { fd[cpu][counter][0] = sys_perf_event_open(attr, -1, cpumap[cpu], -1, 0); - if (fd[cpu][counter][0] < 0 && verbose) - fprintf(stderr, ERR_PERF_OPEN, counter, - fd[cpu][counter][0], strerror(errno)); + if (fd[cpu][counter][0] < 0) + pr_debug(ERR_PERF_OPEN, counter, + fd[cpu][counter][0], strerror(errno)); + else + ++ncreated; } } else { attr->inherit = inherit; @@ -172,12 +175,16 @@ static void create_perf_stat_counter(int counter) for (thread = 0; thread < thread_num; thread++) { fd[0][counter][thread] = sys_perf_event_open(attr, all_tids[thread], -1, -1, 0); - if (fd[0][counter][thread] < 0 && verbose) - fprintf(stderr, ERR_PERF_OPEN, counter, - fd[0][counter][thread], - strerror(errno)); + if (fd[0][counter][thread] < 0) + pr_debug(ERR_PERF_OPEN, counter, + fd[0][counter][thread], + strerror(errno)); + else + ++ncreated; } } + + return ncreated; } /* @@ -264,7 +271,7 @@ static int run_perf_stat(int argc __used, const char **argv) { unsigned long long t0, t1; int status = 0; - int counter; + int counter, ncreated = 0; int child_ready_pipe[2], go_pipe[2]; const bool forks = (argc > 0); char buf; @@ -324,7 +331,16 @@ static int run_perf_stat(int argc __used, const char **argv) } for (counter = 0; counter < nr_counters; counter++) - create_perf_stat_counter(counter); + ncreated += create_perf_stat_counter(counter); + + if (ncreated == 0) { + pr_err("No permission to collect %sstats.\n" + "Consider tweaking /proc/sys/kernel/perf_event_paranoid.\n", + system_wide ? "system-wide " : ""); + if (child_pid != -1) + kill(child_pid, SIGTERM); + return -1; + } /* * Enable counters and exec the command: @@ -587,7 +603,8 @@ int cmd_stat(int argc, const char **argv, const char *prefix __used) status = run_perf_stat(argc, argv); } - print_stat(argc, argv); + if (status != -1) + print_stat(argc, argv); return status; } -- 1.6.2.5