diff options
| author | Luo Gengkun <luogengkun@huaweicloud.com> | 2025-04-23 06:47:24 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-05-02 07:59:04 +0200 |
| commit | 8d37031464d552d27c2dce98da9ab86ca00d71b6 (patch) | |
| tree | 0228868c73a6d6e4b7b3d5a52aab0f2ed561ff43 | |
| parent | 955f9ede52b8617e454fcfd4528f90bd23a30753 (diff) | |
perf/x86: Fix non-sampling (counting) events on certain x86 platforms
[ Upstream commit 1a97fea9db9e9b9c4839d4232dde9f505ff5b4cc ]
Perf doesn't work at perf stat for hardware events on certain x86 platforms:
$perf stat -- sleep 1
Performance counter stats for 'sleep 1':
16.44 msec task-clock # 0.016 CPUs utilized
2 context-switches # 121.691 /sec
0 cpu-migrations # 0.000 /sec
54 page-faults # 3.286 K/sec
<not supported> cycles
<not supported> instructions
<not supported> branches
<not supported> branch-misses
The reason is that the check in x86_pmu_hw_config() for sampling events is
unexpectedly applied to counting events as well.
It should only impact x86 platforms with limit_period used for non-PEBS
events. For Intel platforms, it should only impact some older platforms,
e.g., HSW, BDW and NHM.
Fixes: 88ec7eedbbd2 ("perf/x86: Fix low freqency setting issue")
Signed-off-by: Luo Gengkun <luogengkun@huaweicloud.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/r/20250423064724.3716211-1-luogengkun@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | arch/x86/events/core.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index 0d33c85da453..d737d53d03aa 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -628,7 +628,7 @@ int x86_pmu_hw_config(struct perf_event *event) if (event->attr.type == event->pmu->type) event->hw.config |= x86_pmu_get_event_config(event); - if (!event->attr.freq && x86_pmu.limit_period) { + if (is_sampling_event(event) && !event->attr.freq && x86_pmu.limit_period) { s64 left = event->attr.sample_period; x86_pmu.limit_period(event, &left); if (left > event->attr.sample_period) |