linux-kernel - [PATCH 2/5] libperf: Propagate maps only if necessary

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: <20220924165737.956428-3-namhyung@kernel.org>
Date:   Sat, 24 Sep 2022 09:57:34 -0700
From:   Namhyung Kim <namhyung@...nel.org>
To:     Arnaldo Carvalho de Melo <acme@...nel.org>,
        Jiri Olsa <jolsa@...nel.org>
Cc:     Ingo Molnar <mingo@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Ian Rogers <irogers@...gle.com>,
        Adrian Hunter <adrian.hunter@...el.com>,
        linux-perf-users@...r.kernel.org,
        Kan Liang <kan.liang@...ux.intel.com>,
        Leo Yan <leo.yan@...aro.org>
Subject: [PATCH 2/5] libperf: Propagate maps only if necessary

The current code propagate evsel's cpu map settings to evlist when it's
added to an evlist.  But the evlist->all_cpus and each evsel's cpus will
be updated in perf_evlist__set_maps() later.  No need to do it before
evlist's cpus are set actually.

Actually we discarded this intermediate all_cpus maps at the beginning
of perf_evlist__set_maps().  Let's not do this.  It's only needed when
an evsel is added after the evlist cpu maps are set.

Signed-off-by: Namhyung Kim <namhyung@...nel.org>
---
 tools/lib/perf/evlist.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/tools/lib/perf/evlist.c b/tools/lib/perf/evlist.c
index 187129652ab6..cc070c3a134d 100644
--- a/tools/lib/perf/evlist.c
+++ b/tools/lib/perf/evlist.c
@@ -67,10 +67,6 @@ static void perf_evlist__propagate_maps(struct perf_evlist *evlist)
 {
 	struct perf_evsel *evsel;
 
-	/* Recomputing all_cpus, so start with a blank slate. */
-	perf_cpu_map__put(evlist->all_cpus);
-	evlist->all_cpus = NULL;
-
 	perf_evlist__for_each_evsel(evlist, evsel)
 		__perf_evlist__propagate_maps(evlist, evsel);
 }
@@ -81,7 +77,9 @@ void perf_evlist__add(struct perf_evlist *evlist,
 	evsel->idx = evlist->nr_entries;
 	list_add_tail(&evsel->node, &evlist->entries);
 	evlist->nr_entries += 1;
-	__perf_evlist__propagate_maps(evlist, evsel);
+
+	if (evlist->all_cpus)
+		__perf_evlist__propagate_maps(evlist, evsel);
 }
 
 void perf_evlist__remove(struct perf_evlist *evlist,
-- 
2.37.3.998.g577e59143f-goog