linux-kernel - [PATCH v4 18/21] perf evlist: Avoid scanning all PMUs for evlist__new

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250914181121.1952748-19-irogers@google.com>
Date: Sun, 14 Sep 2025 11:11:18 -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>, James Clark <james.clark@...aro.org>, 
	Xu Yang <xu.yang_2@....com>, Thomas Falcon <thomas.falcon@...el.com>, 
	Andi Kleen <ak@...ux.intel.com>, linux-kernel@...r.kernel.org, 
	linux-perf-users@...r.kernel.org, bpf@...r.kernel.org, 
	Atish Patra <atishp@...osinc.com>, Beeman Strong <beeman@...osinc.com>, Leo Yan <leo.yan@....com>, 
	Vince Weaver <vincent.weaver@...ne.edu>
Subject: [PATCH v4 18/21] perf evlist: Avoid scanning all PMUs for evlist__new_default

Rather than wildcard matching the cycles event specify only the core
PMUs. This avoids potentially loading unnecessary uncore PMUs.

Signed-off-by: Ian Rogers <irogers@...gle.com>
---
 tools/perf/util/evlist.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 80d8387e6b97..e8217efdda53 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -101,16 +101,24 @@ struct evlist *evlist__new_default(void)
 {
 	struct evlist *evlist = evlist__new();
 	bool can_profile_kernel;
-	int err;
+	struct perf_pmu *pmu = NULL;
 
 	if (!evlist)
 		return NULL;
 
 	can_profile_kernel = perf_event_paranoid_check(1);
-	err = parse_event(evlist, can_profile_kernel ? "cycles:P" : "cycles:Pu");
-	if (err) {
-		evlist__delete(evlist);
-		return NULL;
+
+	while ((pmu = perf_pmus__scan_core(pmu)) != NULL) {
+		char buf[256];
+		int err;
+
+		snprintf(buf, sizeof(buf), "%s/cycles/%s", pmu->name,
+			 can_profile_kernel ? "P" : "Pu");
+		err = parse_event(evlist, buf);
+		if (err) {
+			evlist__delete(evlist);
+			return NULL;
+		}
 	}
 
 	if (evlist->core.nr_entries > 1) {
-- 
2.51.0.384.g4c02a37b29-goog