From: Andrew Kilroy <andrew.kilroy@arm.com>
To: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
acme@kernel.org, john.garry@huawei.com, irogers@google.com,
ak@linux.intel.com
Cc: Andrew Kilroy <andrew.kilroy@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>
Subject: [RFC PATCH v2 5/5] perf stat: Ensure only topdown kernel events used on x86
Date: Tue, 11 Jan 2022 15:07:49 +0000 [thread overview]
Message-ID: <20220111150749.13365-6-andrew.kilroy@arm.com> (raw)
In-Reply-To: <20220111150749.13365-1-andrew.kilroy@arm.com>
Based on advice here:
https://lore.kernel.org/linux-perf-users/12e0deef-08db-445f-4958-bcd5c3e10367@linux.intel.com/#t
Only use the existing kernel events topdown mechanism on x86, not the
json metrics approach. Disabling the json metrics because of concerns
that due to SMT it's not straightforward to express the various formulas
as json for certain x86 cpus.
Signed-off-by: Andrew Kilroy <andrew.kilroy@arm.com>
---
tools/perf/builtin-stat.c | 22 +++++++++++++---------
tools/perf/util/topdown.c | 6 +++---
2 files changed, 16 insertions(+), 12 deletions(-)
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 2f579d29f9f5..eee58fbf1986 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -1814,16 +1814,20 @@ enum topdown_mechanism {
static enum topdown_mechanism choose_topdown_mechanism(void)
{
- int kernel_events_supported = topdown_kernel_events_supported();
-
- if (kernel_events_supported > 0) {
- pr_debug("topdown kernel events are supported\n");
- return TOPDOWN_KERNEL_EVENTS;
- } else if (kernel_events_supported == 0) {
- pr_debug("topdown kernel events are unsupported\n");
- return TOPDOWN_JSON_METRICS;
+ if (topdown_can_use_json_metrics()) {
+ int kernel_events_supported = topdown_kernel_events_supported();
+
+ if (kernel_events_supported > 0) {
+ pr_debug("topdown kernel events are supported\n");
+ return TOPDOWN_KERNEL_EVENTS;
+ } else if (kernel_events_supported == 0) {
+ pr_debug("topdown kernel events are unsupported\n");
+ return TOPDOWN_JSON_METRICS;
+ } else {
+ return TOPDOWN_DETECTION_ERROR;
+ }
} else {
- return TOPDOWN_DETECTION_ERROR;
+ return TOPDOWN_KERNEL_EVENTS;
}
}
diff --git a/tools/perf/util/topdown.c b/tools/perf/util/topdown.c
index a542dddd97f3..36f6c29009fb 100644
--- a/tools/perf/util/topdown.c
+++ b/tools/perf/util/topdown.c
@@ -59,10 +59,10 @@ __weak bool arch_topdown_sample_read(struct evsel *leader __maybe_unused)
bool topdown_can_use_json_metrics(void)
{
-#if defined(__aarch64__)
- return true;
-#else
+#if defined(__i386__) || defined(__x86_64__)
return false;
+#else
+ return true;
#endif
}
--
2.17.1
next prev parent reply other threads:[~2022-01-11 15:08 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-10 12:37 [PATCH v2 0/2] perf vendor events: Arm Neoverse N2 Andrew Kilroy
2021-12-10 12:37 ` [PATCH v2 1/2] perf vendor events: For the " Andrew Kilroy
2021-12-10 13:21 ` John Garry
2021-12-14 18:42 ` [RFC PATCH 0/1] topdown with metrics Andrew Kilroy
2021-12-14 18:42 ` [RFC PATCH 1/1] perf arm64: Implement --topdown " Andrew Kilroy
2021-12-14 20:32 ` Ian Rogers
2021-12-15 10:38 ` James Clark
2021-12-15 10:52 ` John Garry
2021-12-15 12:38 ` Andrew Kilroy
2021-12-15 12:53 ` John Garry
2022-01-06 16:33 ` Andrew Kilroy
2022-01-06 18:24 ` John Garry
2022-01-11 15:07 ` [RFC PATCH v2 0/5] topdown " Andrew Kilroy
2022-01-11 15:07 ` [RFC PATCH v2 1/5] perf stat: Implement --topdown " Andrew Kilroy
2022-01-28 13:44 ` John Garry
2022-01-11 15:07 ` [RFC PATCH v2 2/5] perf stat: Topdown kernel events setup function Andrew Kilroy
2022-01-11 15:07 ` [RFC PATCH v2 3/5] perf stat: Topdown json metrics " Andrew Kilroy
2022-01-11 15:07 ` [RFC PATCH v2 4/5] perf stat: Detect if topdown kernel events supported Andrew Kilroy
2022-01-11 15:07 ` Andrew Kilroy [this message]
2022-01-20 9:26 ` [RFC PATCH v2 0/5] topdown with metrics John Garry
2022-01-20 16:22 ` Al Grant
2022-01-27 11:42 ` Andrew Kilroy
2022-02-08 15:58 ` Andrew Kilroy
2021-12-20 17:21 ` [RFC PATCH 1/1] perf arm64: Implement --topdown " Andrew Kilroy
2021-12-21 14:03 ` Andi Kleen
2022-01-27 11:11 ` Andrew Kilroy
2021-12-17 10:19 ` John Garry
2021-12-21 14:31 ` Andrew Kilroy
2022-01-05 16:58 ` Andrew Kilroy
2022-01-28 18:00 ` John Garry
2021-12-10 12:37 ` [PATCH v2 2/2] perf vendor events: Rename arm64 arch std event files Andrew Kilroy
2021-12-10 13:46 ` John Garry
2021-12-10 19:01 ` Arnaldo Carvalho de Melo
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