From: Ian Rogers <irogers@google.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>, Andrii Nakryiko <andriin@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@chromium.org>,
Adrian Hunter <adrian.hunter@intel.com>,
Andi Kleen <ak@linux.intel.com>,
Athira Rajeev <atrajeev@linux.vnet.ibm.com>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
bpf@vger.kernel.org
Cc: Stephane Eranian <eranian@google.com>, Ian Rogers <irogers@google.com>
Subject: [PATCH v3 2/4] perf record: Prevent override of attr->sample_period for libpfm4 events
Date: Fri, 11 Sep 2020 19:56:53 -0700 [thread overview]
Message-ID: <20200912025655.1337192-3-irogers@google.com> (raw)
In-Reply-To: <20200912025655.1337192-1-irogers@google.com>
From: Stephane Eranian <eranian@google.com>
Before:
$ perf record -c 10000 --pfm-events=cycles:period=77777
Would yield a cycles event with period=10000, instead of 77777.
This was due to an ordering issue between libpfm4 parsing
the event string and perf record initializing the event.
This patch fixes the problem by preventing override for
events with attr->sample_period != 0 by the time
perf_evsel__config() is invoked. This seems to have been the
intent of the author.
Signed-off-by: Stephane Eranian <eranian@google.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/evsel.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 3e985016da7e..459b51e90063 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -976,8 +976,7 @@ 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 || (opts->user_freq != UINT_MAX ||
- opts->user_interval != ULLONG_MAX)) {
+ if (!attr->sample_period) {
if (opts->freq) {
attr->freq = 1;
attr->sample_freq = opts->freq;
--
2.28.0.618.gf4bc123cb7-goog
next prev parent reply other threads:[~2020-09-12 2:57 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-12 2:56 [PATCH v3 0/4] Fixes for setting event freq/periods Ian Rogers
2020-09-12 2:56 ` [PATCH v3 1/4] perf record: Set PERF_RECORD_PERIOD if attr->freq is set Ian Rogers
2020-09-12 2:56 ` Ian Rogers [this message]
2020-09-12 2:56 ` [PATCH v3 3/4] perf record: Don't clear event's period if set by a term Ian Rogers
2020-09-14 6:02 ` Adrian Hunter
2020-09-14 21:46 ` Arnaldo Carvalho de Melo
2020-09-14 21:51 ` Arnaldo Carvalho de Melo
2020-09-14 21:52 ` Ian Rogers
2020-09-14 22:34 ` Arnaldo Carvalho de Melo
2020-09-12 2:56 ` [PATCH v3 4/4] perf test: Leader sampling shouldn't clear sample period Ian Rogers
2020-09-14 22:36 ` Arnaldo Carvalho de Melo
2020-09-12 20:49 ` [PATCH v3 0/4] Fixes for setting event freq/periods Jiri Olsa
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