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perf evsel: Override attr->sample_period for non-libpfm4 events 

A previous patch preventing "attr->sample_period" values from being
overridden in pfm events changed a related behaviour in arm-spe.

Before said patch:

  perf record -c 10000 -e arm_spe_0// -- sleep 1

Would yield an SPE event with period=10000. After the patch, the period
in "-c 10000" was being ignored because the arm-spe code initializes
sample_period to a non-zero value.

This patch restores the previous behaviour for non-libpfm4 events.

Fixes: ae5dcc8abe (“perf record: Prevent override of attr->sample_period for libpfm4 events”)
Reported-by: Chase Conklin <chase.conklin@arm.com>
Signed-off-by: German Gomez <german.gomez@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: http://lore.kernel.org/lkml/20220118144054.2541-1-german.gomez@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
German Gomez 2022-01-18 14:40:54 +00:00 committed by Arnaldo Carvalho de Melo
parent 24ead7c254
commit 3606c0e1a1
1 changed files with 17 additions and 8 deletions
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25
tools/perf/util/evsel.c
View File

@ -1064,6 +1064,17 @@ void __weak arch_evsel__fixup_new_cycles(struct perf_event_attr *attr __maybe_un
{
}
static void evsel__set_default_freq_period(struct record_opts *opts,
struct perf_event_attr *attr)
{
if (opts->freq) {
attr->freq = 1;
attr->sample_freq = opts->freq;
} else {
attr->sample_period = opts->default_interval;
}
}
/*
* The enable_on_exec/disabled value strategy:
*
@ -1130,14 +1141,12 @@ void evsel__config(struct evsel *evsel, struct record_opts *opts,
* We default some events to have a default interval. But keep
* it a weak assumption overridable by the user.
*/
if (!attr->sample_period) {
if (opts->freq) {
attr->freq = 1;
attr->sample_freq = opts->freq;
} else {
attr->sample_period = opts->default_interval;
}
}
if ((evsel->is_libpfm_event && !attr->sample_period) ||
(!evsel->is_libpfm_event && (!attr->sample_period ||
opts->user_freq != UINT_MAX ||
opts->user_interval != ULLONG_MAX)))
evsel__set_default_freq_period(opts, attr);
/*
* If attr->freq was set (here or earlier), ask for period
* to be sampled.