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| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2022-01-17 13:09:29 -0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2022-01-18 09:24:58 -0300 |
| commit | 49de179577e7b05b57f625bf05cdc60a72de38d0 (patch) | |
| tree | 21404b5c8dc4ba66b120a50c0121b9477f45907f | |
| parent | 1855b796f2f672cbb25400be2d3171c26fc869a3 (diff) | |
| download | linux-49de179577e7b05b57f625bf05cdc60a72de38d0.tar.gz linux-49de179577e7b05b57f625bf05cdc60a72de38d0.tar.xz | |
perf stat: No need to setup affinities when starting a workload
I.e. the simple:
$ perf stat sleep 1
Uses a dummy CPU map and thus there is no need to setup/cleanup
affinities to avoid IPIs, etc.
With this we're down to a sched_getaffinity() call, in the libnuma
initialization, that probably can be removed in a followup patch.
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20220117160931.1191712-3-acme@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| -rw-r--r-- | tools/perf/builtin-stat.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index 973ade18b72a..934e992c966f 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -788,7 +788,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) const bool forks = (argc > 0); bool is_pipe = STAT_RECORD ? perf_stat.data.is_pipe : false; struct evlist_cpu_iterator evlist_cpu_itr; - struct affinity affinity; + struct affinity saved_affinity, *affinity = NULL; int err; bool second_pass = false; @@ -803,8 +803,11 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) if (group) evlist__set_leader(evsel_list); - if (affinity__setup(&affinity) < 0) - return -1; + if (!cpu_map__is_dummy(evsel_list->core.cpus)) { + if (affinity__setup(&saved_affinity) < 0) + return -1; + affinity = &saved_affinity; + } evlist__for_each_entry(evsel_list, counter) { if (bpf_counter__load(counter, &target)) @@ -813,7 +816,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) all_counters_use_bpf = false; } - evlist__for_each_cpu(evlist_cpu_itr, evsel_list, &affinity) { + evlist__for_each_cpu(evlist_cpu_itr, evsel_list, affinity) { counter = evlist_cpu_itr.evsel; /* @@ -869,7 +872,7 @@ try_again: */ /* First close errored or weak retry */ - evlist__for_each_cpu(evlist_cpu_itr, evsel_list, &affinity) { + evlist__for_each_cpu(evlist_cpu_itr, evsel_list, affinity) { counter = evlist_cpu_itr.evsel; if (!counter->reset_group && !counter->errored) @@ -878,7 +881,7 @@ try_again: perf_evsel__close_cpu(&counter->core, evlist_cpu_itr.cpu_map_idx); } /* Now reopen weak */ - evlist__for_each_cpu(evlist_cpu_itr, evsel_list, &affinity) { + evlist__for_each_cpu(evlist_cpu_itr, evsel_list, affinity) { counter = evlist_cpu_itr.evsel; if (!counter->reset_group && !counter->errored) @@ -904,7 +907,7 @@ try_again_reset: counter->supported = true; } } - affinity__cleanup(&affinity); + affinity__cleanup(affinity); evlist__for_each_entry(evsel_list, counter) { if (!counter->supported) { |