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| author | Namhyung Kim <namhyung@kernel.org> | 2024-05-09 11:22:35 -0700 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2024-05-10 10:52:46 -0300 |
| commit | e2eeef290c4adad7a0f95c4a41e1a992326a7829 (patch) | |
| tree | ff4e6cd1721ee4d10b8c149c6721f1e66d4898f5 /tools/perf/util | |
| parent | 5ceb57990bf41684e9bc186128a07025adb896bd (diff) | |
| download | linux-e2eeef290c4adad7a0f95c4a41e1a992326a7829.tar.gz linux-e2eeef290c4adad7a0f95c4a41e1a992326a7829.tar.bz2 linux-e2eeef290c4adad7a0f95c4a41e1a992326a7829.zip | |
perf tools: Ignore deleted cgroups
On large systems, cgroups can be created and deleted often. That means
there's a race between perf tools and cgroups when it gets the cgroup
name and opens the cgroup.
I got a report that 'perf stat' with many cgroups failed quite often due
to the missing cgroups on such a large machine.
I think we can ignore such cgroups when expanding events and use id 0 if
it fails to read the cgroup id. IIUC 0 is not a vaild cgroup id so it
won't update event counts for the failed cgroups.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240509182235.2319599-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util')
| -rw-r--r-- | tools/perf/util/bpf_counter_cgroup.c | 5 | ||||
| -rw-r--r-- | tools/perf/util/cgroup.c | 4 |
2 files changed, 5 insertions, 4 deletions
diff --git a/tools/perf/util/bpf_counter_cgroup.c b/tools/perf/util/bpf_counter_cgroup.c index 1c82377ed78b..ea29c372f339 100644 --- a/tools/perf/util/bpf_counter_cgroup.c +++ b/tools/perf/util/bpf_counter_cgroup.c @@ -136,9 +136,8 @@ static int bperf_load_program(struct evlist *evlist) cgrp = evsel->cgrp; if (read_cgroup_id(cgrp) < 0) { - pr_err("Failed to get cgroup id\n"); - err = -1; - goto out; + pr_debug("Failed to get cgroup id for %s\n", cgrp->name); + cgrp->id = 0; } map_fd = bpf_map__fd(skel->maps.cgrp_idx); diff --git a/tools/perf/util/cgroup.c b/tools/perf/util/cgroup.c index fcb509058499..0f759dd96db7 100644 --- a/tools/perf/util/cgroup.c +++ b/tools/perf/util/cgroup.c @@ -465,9 +465,11 @@ int evlist__expand_cgroup(struct evlist *evlist, const char *str, name = cn->name + prefix_len; if (name[0] == '/' && name[1]) name++; + + /* the cgroup can go away in the meantime */ cgrp = cgroup__new(name, open_cgroup); if (cgrp == NULL) - goto out_err; + continue; leader = NULL; evlist__for_each_entry(orig_list, pos) { |