Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757601Ab1BQSTp (ORCPT ); Thu, 17 Feb 2011 13:19:45 -0500 Received: from smtp-out.google.com ([74.125.121.67]:29002 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757093Ab1BQSTm convert rfc822-to-8bit (ORCPT ); Thu, 17 Feb 2011 13:19:42 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=w4REBF8s1lDcE4U8GV3uXwV1BP/TtYNHeHcrzZAEX63y5QxqvWf6H6KpHvO+UcxEwo 7VG/9kAQONRRH4mJlvSw== MIME-Version: 1.0 In-Reply-To: <20110217152313.GD10805@ghostprotocols.net> References: <20110217152313.GD10805@ghostprotocols.net> Date: Thu, 17 Feb 2011 19:19:37 +0100 Message-ID: Subject: Re: [BUG] perf: perf report -n shows bogus number of samples From: Stephane Eranian To: Arnaldo Carvalho de Melo Cc: LKML , mingo@elte.hu, Peter Zijlstra , =?UTF-8?B?RnLDqWTDqXJpYyBXZWlzYmVja2Vy?= , perfmon2-devel@lists.sf.net Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6015 Lines: 123 On Thu, Feb 17, 2011 at 4:23 PM, Arnaldo Carvalho de Melo wrote: > Em Wed, Feb 09, 2011 at 12:34:44AM +0100, Stephane Eranian escreveu: >> I think the -n option of perf report shows bogus number of samples. >> >> I believe it does not print the number of samples but rather the >> number of events if I understand the code in hist_entry__snprintf(). >> I think that's useless, the number of samples is more useful. > > >> $ perf record -e cycles ./repmov >> $ perf report -D | fgrep RECORD_SAMPLE | wc -l >> 86346 >> $ ./perf report -n >> # Events: 86K cycles >> # >> # Overhead Samples Command Shared Object Symbol >> # ........ .......... ....... ................. ......................... >> # >> 98.92%238206388334 repmov repmov [.] main >> 0.08% 189506224 repmov [kernel.kallsyms] [k] perf_ctx_adjust_freq >> 0.06% 147582706 repmov [kernel.kallsyms] [k] perf_event_task_tick >> >> It should be easy to reproduce with any other program. > > Like this? Can I have your acked-by? > Yes. Works for me. Acked-by: Stephane Eranian > commit 58e57f4dd6164bdbd5bc1f7d7c1ba5eb104e9b32 > Author: Arnaldo Carvalho de Melo > Date: Thu Feb 17 10:37:23 2011 -0200 > > perf hists: Print number of samples, not the period sum > > So that we match the header where we state the number of events with the > "Samples" column when using 'perf report -n/--show-nr-samples': > > [root@emilia ~]# perf record -a sleep 1 > [ perf record: Woken up 1 times to write data ] > [ perf record: Captured and wrote 0.111 MB perf.data (~4860 samples) ] > [root@emilia ~]# perf report --stdio --show-nr-samples > # Events: 11 cycles > # > # Overhead Samples Command Shared Object Symbol > # ........ .......... ........... .................. ............................ > # > 16.65% 1 sleep [kernel.kallsyms] [k] unmap_vmas > 16.10% 1 perf libpthread-2.12.so [.] __pthread_cleanup_push_defer > 15.79% 2 perf [kernel.kallsyms] [k] format_decode > 12.88% 1 kworker/1:2 [kernel.kallsyms] [k] cache_reap > 10.69% 1 swapper [kernel.kallsyms] [k] _raw_spin_lock > 7.55% 1 sleep [kernel.kallsyms] [k] prepare_exec_creds > 6.00% 1 perf [jbd2] [k] start_this_handle > 5.29% 1 perf [kernel.kallsyms] [k] seq_read > 4.75% 1 perf [kernel.kallsyms] [k] get_pid_task > 4.30% 1 perf [kernel.kallsyms] [k] _raw_spin_unlock_irqrestore > > # > # (For a higher level overview, try: perf report --sort comm,dso) > # > [root@emilia ~]# > > Reported-by: Stephane Eranian > Cc: Frederic Weisbecker > Cc: Ingo Molnar > Cc: Mike Galbraith > Cc: Paul Mackerras > Cc: Peter Zijlstra > Cc: Stephane Eranian > Cc: Tom Zanussi > LKML-Reference: > Signed-off-by: Arnaldo Carvalho de Melo > > diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c > index 3f43723..da2899e 100644 > --- a/tools/perf/util/hist.c > +++ b/tools/perf/util/hist.c > @@ -591,6 +591,7 @@ int hist_entry__snprintf(struct hist_entry *self, char *s, size_t size, > { > struct sort_entry *se; > u64 period, total, period_sys, period_us, period_guest_sys, period_guest_us; > + u64 nr_events; > const char *sep = symbol_conf.field_sep; > int ret; > > @@ -599,6 +600,7 @@ int hist_entry__snprintf(struct hist_entry *self, char *s, size_t size, > > if (pair_hists) { > period = self->pair ? self->pair->period : 0; > + nr_events = self->pair ? self->pair->nr_events : 0; > total = pair_hists->stats.total_period; > period_sys = self->pair ? self->pair->period_sys : 0; > period_us = self->pair ? self->pair->period_us : 0; > @@ -606,6 +608,7 @@ int hist_entry__snprintf(struct hist_entry *self, char *s, size_t size, > period_guest_us = self->pair ? self->pair->period_guest_us : 0; > } else { > period = self->period; > + nr_events = self->nr_events; > total = session_total; > period_sys = self->period_sys; > period_us = self->period_us; > @@ -646,9 +649,9 @@ int hist_entry__snprintf(struct hist_entry *self, char *s, size_t size, > > if (symbol_conf.show_nr_samples) { > if (sep) > - ret += snprintf(s + ret, size - ret, "%c%" PRIu64, *sep, period); > + ret += snprintf(s + ret, size - ret, "%c%" PRIu64, *sep, nr_events); > else > - ret += snprintf(s + ret, size - ret, "%11" PRIu64, period); > + ret += snprintf(s + ret, size - ret, "%11" PRIu64, nr_events); > } > > if (pair_hists) { > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/