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Message-ID: <20250326035045.129440-3-irogers@google.com>
Date: Tue, 25 Mar 2025 20:50:43 -0700
From: Ian Rogers <irogers@...gle.com>
To: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>,
Arnaldo Carvalho de Melo <acme@...nel.org>, Namhyung Kim <namhyung@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>, Jiri Olsa <jolsa@...nel.org>,
Ian Rogers <irogers@...gle.com>, Adrian Hunter <adrian.hunter@...el.com>,
Kan Liang <kan.liang@...ux.intel.com>,
"Masami Hiramatsu (Google)" <mhiramat@...nel.org>, James Clark <james.clark@...aro.org>,
Weilin Wang <weilin.wang@...el.com>, Dominique Martinet <asmadeus@...ewreck.org>,
Thomas Richter <tmricht@...ux.ibm.com>, Junhao He <hejunhao3@...wei.com>,
Jean-Philippe Romain <jean-philippe.romain@...s.st.com>, linux-kernel@...r.kernel.org,
linux-perf-users@...r.kernel.org
Cc: dri-devel@...ts.freedesktop.org
Subject: [PATCH v2 2/4] perf parse-events: Avoid scanning PMUs that can't
match a wildcard
Add perf_pmus__scan_matching_wildcard that only reads sysfs for pmus
that could wildcard match. For example, if searching for the event
'inst_retired.any/period=1000000/' first 'inst_retired.any' will try
to be directly looked up as a PMU, then 'inst_retired.any' will try to
be wildcard matched against all PMUs, finally it is assumed
'inst_retired.any' is an event name and opened on all PMUs avoiding
reading PMUs that can't have such an event. However, before this patch
such a case would read all PMUs for the wildcard matching. Now if the
wildcard can't be a hwmon PMU wildcard, reading hwmon PMUs is
avoided. On my laptop this reduces 'perf stat -e inst_retired.any
true' from performing 253 openat system calls down to 234.
Signed-off-by: Ian Rogers <irogers@...gle.com>
---
tools/perf/util/parse-events.c | 26 +++++++++++----------
tools/perf/util/pmus.c | 42 ++++++++++++++++++++++++++++++++++
tools/perf/util/pmus.h | 1 +
3 files changed, 57 insertions(+), 12 deletions(-)
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index d77af1d24985..19caf1ed9f5d 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -1664,18 +1664,20 @@ int parse_events_multi_pmu_add_or_add_pmu(struct parse_events_state *parse_state
pmu = NULL;
/* Failed to add, try wildcard expansion of event_or_pmu as a PMU name. */
- while ((pmu = perf_pmus__scan(pmu)) != NULL) {
- if (!parse_events__filter_pmu(parse_state, pmu) &&
- perf_pmu__wildcard_match(pmu, event_or_pmu)) {
- bool auto_merge_stats = perf_pmu__auto_merge_stats(pmu);
-
- if (!parse_events_add_pmu(parse_state, *listp, pmu,
- const_parsed_terms,
- auto_merge_stats,
- /*alternate_hw_config=*/PERF_COUNT_HW_MAX)) {
- ok++;
- parse_state->wild_card_pmus = true;
- }
+ while ((pmu = perf_pmus__scan_matching_wildcard(pmu, event_or_pmu)) != NULL) {
+ bool auto_merge_stats;
+
+ if (parse_events__filter_pmu(parse_state, pmu))
+ continue;
+
+ auto_merge_stats = perf_pmu__auto_merge_stats(pmu);
+
+ if (!parse_events_add_pmu(parse_state, *listp, pmu,
+ const_parsed_terms,
+ auto_merge_stats,
+ /*alternate_hw_config=*/PERF_COUNT_HW_MAX)) {
+ ok++;
+ parse_state->wild_card_pmus = true;
}
}
if (ok)
diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
index f2706c395509..93d5db1c89b4 100644
--- a/tools/perf/util/pmus.c
+++ b/tools/perf/util/pmus.c
@@ -19,6 +19,7 @@
#include "tool_pmu.h"
#include "print-events.h"
#include "strbuf.h"
+#include "string2.h"
/*
* core_pmus: A PMU belongs to core_pmus if it's name is "cpu" or it's sysfs
@@ -385,6 +386,47 @@ struct perf_pmu *perf_pmus__scan_for_event(struct perf_pmu *pmu, const char *eve
return NULL;
}
+struct perf_pmu *perf_pmus__scan_matching_wildcard(struct perf_pmu *pmu, const char *wildcard)
+{
+ bool use_core_pmus = !pmu || pmu->is_core;
+
+ if (!pmu) {
+ /*
+ * Core PMUs, other sysfs PMUs and tool PMU can have any name or
+ * aren't wother optimizing for.
+ */
+ unsigned int to_read_pmus = PERF_TOOL_PMU_TYPE_PE_CORE_MASK |
+ PERF_TOOL_PMU_TYPE_PE_OTHER_MASK |
+ PERF_TOOL_PMU_TYPE_TOOL_MASK;
+
+ /*
+ * Hwmon PMUs have an alias from a sysfs name like hwmon0,
+ * hwmon1, etc. or have a name of hwmon_<name>. They therefore
+ * can only have a wildcard match if the wildcard begins with
+ * "hwmon".
+ */
+ if (strisglob(wildcard) ||
+ (strlen(wildcard) >= 5 && strncmp("hwmon", wildcard, 5) == 0))
+ to_read_pmus |= PERF_TOOL_PMU_TYPE_HWMON_MASK;
+
+ pmu_read_sysfs(to_read_pmus);
+ pmu = list_prepare_entry(pmu, &core_pmus, list);
+ }
+ if (use_core_pmus) {
+ list_for_each_entry_continue(pmu, &core_pmus, list) {
+ if (perf_pmu__wildcard_match(pmu, wildcard))
+ return pmu;
+ }
+ pmu = NULL;
+ pmu = list_prepare_entry(pmu, &other_pmus, list);
+ }
+ list_for_each_entry_continue(pmu, &other_pmus, list) {
+ if (perf_pmu__wildcard_match(pmu, wildcard))
+ return pmu;
+ }
+ return NULL;
+}
+
static struct perf_pmu *perf_pmus__scan_skip_duplicates(struct perf_pmu *pmu)
{
bool use_core_pmus = !pmu || pmu->is_core;
diff --git a/tools/perf/util/pmus.h b/tools/perf/util/pmus.h
index 213ee65306d6..2794d8c3a466 100644
--- a/tools/perf/util/pmus.h
+++ b/tools/perf/util/pmus.h
@@ -20,6 +20,7 @@ struct perf_pmu *perf_pmus__find_by_type(unsigned int type);
struct perf_pmu *perf_pmus__scan(struct perf_pmu *pmu);
struct perf_pmu *perf_pmus__scan_core(struct perf_pmu *pmu);
struct perf_pmu *perf_pmus__scan_for_event(struct perf_pmu *pmu, const char *event);
+struct perf_pmu *perf_pmus__scan_matching_wildcard(struct perf_pmu *pmu, const char *wildcard);
const struct perf_pmu *perf_pmus__pmu_for_pmu_filter(const char *str);
--
2.49.0.395.g12beb8f557-goog
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