From 7736627b865defff2430e95df235b4aa2450bc37 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Wed, 20 Nov 2019 16:15:17 -0800 Subject: [PATCH] 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 Acked-by: Jiri Olsa Link: http://lore.kernel.org/lkml/20191121001522.180827-8-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo --- 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 dae6e846b2f8..2e8d38a324be 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -18,6 +18,7 @@ #include "debug.h" #include "units.h" #include // 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)