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.
<SNIP
> $ 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?
commit 58e57f4dd6164bdbd5bc1f7d7c1ba5eb104e9b32
Author: Arnaldo Carvalho de Melo <a...@redhat.com>
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 <eran...@google.com>
Cc: Frederic Weisbecker <fweis...@gmail.com>
Cc: Ingo Molnar <mi...@elte.hu>
Cc: Mike Galbraith <efa...@gmx.de>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Stephane Eranian <eran...@google.com>
Cc: Tom Zanussi <tzanu...@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com>
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) {
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