From 539e6bb71e350541105e67e3d6c31392d9da25ef Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Fri, 1 Nov 2013 15:51:34 +0200 Subject: [PATCH] perf record: Add an option to force per-cpu mmaps By default, when tasks are specified (i.e. -p, -t or -u options) per-thread mmaps are created. Add an option to override that and force per-cpu mmaps. Further comments by peterz: So this option allows -t/-p/-u to create one buffer per cpu and attach all the various thread/process/user tasks' their counters to that one buffer? As opposed to the current state where each such counter would have its own buffer. Signed-off-by: Adrian Hunter Tested-by: Sukadev Bhattiprolu Acked-by: Peter Zijlstra Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1383313899-15987-7-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/Documentation/perf-record.txt | 6 ++++++ tools/perf/builtin-record.c | 2 ++ tools/perf/util/evlist.c | 4 +++- tools/perf/util/evsel.c | 4 ++-- tools/perf/util/target.h | 1 + 5 files changed, 14 insertions(+), 3 deletions(-) diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 052f7c4dc00c..43b42c4f4a91 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -201,6 +201,12 @@ abort events and some memory events in precise mode on modern Intel CPUs. --transaction:: Record transaction flags for transaction related events. +--force-per-cpu:: +Force the use of per-cpu mmaps. By default, when tasks are specified (i.e. -p, +-t or -u options) per-thread mmaps are created. This option overrides that and +forces per-cpu mmaps. A side-effect of that is that inheritance is +automatically enabled. Add the -i option also to disable inheritance. + SEE ALSO -------- linkperf:perf-stat[1], linkperf:perf-list[1] diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 4d644fe2d5b7..7c8020a32784 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -888,6 +888,8 @@ const struct option record_options[] = { "sample by weight (on special events only)"), OPT_BOOLEAN(0, "transaction", &record.opts.sample_transaction, "sample transaction flags (special events only)"), + OPT_BOOLEAN(0, "force-per-cpu", &record.opts.target.force_per_cpu, + "force the use of per-cpu mmaps"), OPT_END() }; diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 5ce2ace2d6c1..bbc746aa5716 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -819,7 +819,9 @@ int perf_evlist__create_maps(struct perf_evlist *evlist, struct target *target) if (evlist->threads == NULL) return -1; - if (target__has_task(target)) + if (target->force_per_cpu) + evlist->cpus = cpu_map__new(target->cpu_list); + else if (target__has_task(target)) evlist->cpus = cpu_map__dummy_new(); else if (!target__has_cpu(target) && !target->uses_mmap) evlist->cpus = cpu_map__dummy_new(); diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 18f7c188ff63..46dd4c2a41ce 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -645,7 +645,7 @@ void perf_evsel__config(struct perf_evsel *evsel, } } - if (target__has_cpu(&opts->target)) + if (target__has_cpu(&opts->target) || opts->target.force_per_cpu) perf_evsel__set_sample_bit(evsel, CPU); if (opts->period) @@ -653,7 +653,7 @@ void perf_evsel__config(struct perf_evsel *evsel, if (!perf_missing_features.sample_id_all && (opts->sample_time || !opts->no_inherit || - target__has_cpu(&opts->target))) + target__has_cpu(&opts->target) || opts->target.force_per_cpu)) perf_evsel__set_sample_bit(evsel, TIME); if (opts->raw_samples) { diff --git a/tools/perf/util/target.h b/tools/perf/util/target.h index 89bab7129de4..2d0c50690892 100644 --- a/tools/perf/util/target.h +++ b/tools/perf/util/target.h @@ -12,6 +12,7 @@ struct target { uid_t uid; bool system_wide; bool uses_mmap; + bool force_per_cpu; }; enum target_errno {