Messages in this thread Patch in this message | | | Date | Wed, 04 Dec 2019 07:53:54 -0000 | From | "tip-bot2 for Andi Kleen" <> | Subject | [tip: perf/urgent] perf stat: Use affinity for closing file descriptors |
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The following commit has been merged into the perf/urgent branch of tip:
Commit-ID: 7736627b865defff2430e95df235b4aa2450bc37 Gitweb: https://git.kernel.org/tip/7736627b865defff2430e95df235b4aa2450bc37 Author: Andi Kleen <ak@linux.intel.com> AuthorDate: Wed, 20 Nov 2019 16:15:17 -08:00 Committer: Arnaldo Carvalho de Melo <acme@redhat.com> CommitterDate: Fri, 29 Nov 2019 12:20:45 -03:00
perf stat: Use affinity for closing file descriptors
Closing a perf fd can also trigger an IPI to the target CPU.
Use the same affinity technique as we use for reading/enabling events to closing to optimize the CPU transitions.
Before on a large test case with 94 CPUs:
% time seconds usecs/call calls errors syscall ------ ----------- ----------- --------- --------- ---------------- 32.56 3.085463 50 61483 close
After:
10.54 0.735704 11 61485 close
Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: http://lore.kernel.org/lkml/20191121001522.180827-8-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> --- tools/perf/util/evlist.c | 31 +++++++++++++++++++++++++++++-- 1 file changed, 29 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index dae6e84..2e8d38a 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -18,6 +18,7 @@ #include "debug.h" #include "units.h" #include <internal/lib.h> // page_size +#include "affinity.h" #include "../perf.h" #include "asm/bug.h" #include "bpf-event.h" @@ -1169,9 +1170,35 @@ void perf_evlist__set_selected(struct evlist *evlist, void evlist__close(struct evlist *evlist) { struct evsel *evsel; + struct affinity affinity; + int cpu, i; - evlist__for_each_entry_reverse(evlist, evsel) - evsel__close(evsel); + /* + * With perf record core.cpus is usually NULL. + * Use the old method to handle this for now. + */ + if (!evlist->core.cpus) { + evlist__for_each_entry_reverse(evlist, evsel) + evsel__close(evsel); + return; + } + + if (affinity__setup(&affinity) < 0) + return; + evlist__for_each_cpu(evlist, i, cpu) { + affinity__set(&affinity, cpu); + + evlist__for_each_entry_reverse(evlist, evsel) { + if (evsel__cpu_iter_skip(evsel, cpu)) + continue; + perf_evsel__close_cpu(&evsel->core, evsel->cpu_iter - 1); + } + } + affinity__cleanup(&affinity); + evlist__for_each_entry_reverse(evlist, evsel) { + perf_evsel__free_fd(&evsel->core); + perf_evsel__free_id(&evsel->core); + } } static int perf_evlist__create_syswide_maps(struct evlist *evlist)
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