From: Ian Rogers irogers@google.com
[ Upstream commit 24852ef2e2d5c555c2da05baff112ea414b6e0f5 ]
The msr PMU is a software one, meaning msr events may be grouped with events in a hardware context. As the msr PMU isn't marked as a software PMU by perf_pmu__is_software, groups with the msr PMU in are broken and the msr events placed in a different group. This may lead to multiplexing errors where a hardware event isn't counted while the msr event, such as tsc, is. Fix all of this by marking the msr PMU as software, which agrees with the driver.
Before: ``` $ perf stat -e '{slots,tsc}' -a true WARNING: events were regrouped to match PMUs
Performance counter stats for 'system wide':
1,750,335 slots 4,243,557 tsc
0.001456717 seconds time elapsed ```
After: ``` $ perf stat -e '{slots,tsc}' -a true Performance counter stats for 'system wide':
12,526,380 slots 3,415,163 tsc
0.001488360 seconds time elapsed ```
Fixes: 251aa040244a ("perf parse-events: Wildcard most "numeric" events") Signed-off-by: Ian Rogers irogers@google.com Reviewed-by: Kan Liang kan.liang@linux.intel.com Cc: James Clark james.clark@arm.com Cc: Caleb Biggers caleb.biggers@intel.com Cc: Edward Baker edward.baker@intel.com Cc: Perry Taylor perry.taylor@intel.com Cc: Samantha Alt samantha.alt@intel.com Cc: Weilin Wang weilin.wang@intel.com Link: https://lore.kernel.org/r/20240124234200.1510417-1-irogers@google.com Signed-off-by: Namhyung Kim namhyung@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/util/pmu.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index d515ba8a0e160..a3c7814116c7c 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -1735,6 +1735,12 @@ bool pmu__name_match(const struct perf_pmu *pmu, const char *pmu_name)
bool perf_pmu__is_software(const struct perf_pmu *pmu) { + const char *known_sw_pmus[] = { + "kprobe", + "msr", + "uprobe", + }; + if (pmu->is_core || pmu->is_uncore || pmu->auxtrace) return false; switch (pmu->type) { @@ -1746,7 +1752,11 @@ bool perf_pmu__is_software(const struct perf_pmu *pmu) case PERF_TYPE_BREAKPOINT: return true; default: break; } - return !strcmp(pmu->name, "kprobe") || !strcmp(pmu->name, "uprobe"); + for (size_t i = 0; i < ARRAY_SIZE(known_sw_pmus); i++) { + if (!strcmp(pmu->name, known_sw_pmus[i])) + return true; + } + return false; }
FILE *perf_pmu__open_file(struct perf_pmu *pmu, const char *name)