From 147c508f3004df6e2958f6c8867909531c2a15e2 Mon Sep 17 00:00:00 2001 From: Jin Yao Date: Mon, 12 Feb 2018 13:32:36 -0700 Subject: [PATCH] perf tools: Use target->per_thread and target->system_wide flags Mathieu Poirier reports issue in commit ("73c0ca1eee3d perf thread_map: Enumerate all threads from /proc") that it has negative impact on 'perf record --per-thread'. It has the effect of creating a kernel event for each thread in the system for 'perf record --per-thread'. Mathieu Poirier's patch ("perf util: Do not reuse target->per_thread flag") can fix this issue by creating a new target->all_threads flag. This patch is based on Mathieu Poirier's patch but it doesn't use a new target->all_threads flag. This patch just uses 'target->per_thread && target->system_wide' as a condition to check for all threads case. Signed-off-by: Jin Yao Cc: Alexander Shishkin Cc: Namhyung Kim Cc: Peter Zijlstra Cc: linux-arm-kernel@lists.infradead.org Fixes: 73c0ca1eee3d ("perf thread_map: Enumerate all threads from /proc") Link: http://lkml.kernel.org/r/1518467557-18505-3-git-send-email-mathieu.poirier@linaro.org Signed-off-by: Mathieu Poirier [Fixed checkpatch warning about line over 80 characters] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/evlist.c | 21 ++++++++++++++++++++- tools/perf/util/thread_map.c | 4 ++-- tools/perf/util/thread_map.h | 2 +- 3 files changed, 23 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index e5fc14e53c05..7b7d535396f7 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -1086,11 +1086,30 @@ int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages) int perf_evlist__create_maps(struct perf_evlist *evlist, struct target *target) { + bool all_threads = (target->per_thread && target->system_wide); struct cpu_map *cpus; struct thread_map *threads; + /* + * If specify '-a' and '--per-thread' to perf record, perf record + * will override '--per-thread'. target->per_thread = false and + * target->system_wide = true. + * + * If specify '--per-thread' only to perf record, + * target->per_thread = true and target->system_wide = false. + * + * So target->per_thread && target->system_wide is false. + * For perf record, thread_map__new_str doesn't call + * thread_map__new_all_cpus. That will keep perf record's + * current behavior. + * + * For perf stat, it allows the case that target->per_thread and + * target->system_wide are all true. It means to collect system-wide + * per-thread data. thread_map__new_str will call + * thread_map__new_all_cpus to enumerate all threads. + */ threads = thread_map__new_str(target->pid, target->tid, target->uid, - target->per_thread); + all_threads); if (!threads) return -1; diff --git a/tools/perf/util/thread_map.c b/tools/perf/util/thread_map.c index 3e1038f6491c..729dad8f412d 100644 --- a/tools/perf/util/thread_map.c +++ b/tools/perf/util/thread_map.c @@ -323,7 +323,7 @@ out_free_threads: } struct thread_map *thread_map__new_str(const char *pid, const char *tid, - uid_t uid, bool per_thread) + uid_t uid, bool all_threads) { if (pid) return thread_map__new_by_pid_str(pid); @@ -331,7 +331,7 @@ struct thread_map *thread_map__new_str(const char *pid, const char *tid, if (!tid && uid != UINT_MAX) return thread_map__new_by_uid(uid); - if (per_thread) + if (all_threads) return thread_map__new_all_cpus(); return thread_map__new_by_tid_str(tid); diff --git a/tools/perf/util/thread_map.h b/tools/perf/util/thread_map.h index 0a806b99e73c..5ec91cfd1869 100644 --- a/tools/perf/util/thread_map.h +++ b/tools/perf/util/thread_map.h @@ -31,7 +31,7 @@ struct thread_map *thread_map__get(struct thread_map *map); void thread_map__put(struct thread_map *map); struct thread_map *thread_map__new_str(const char *pid, - const char *tid, uid_t uid, bool per_thread); + const char *tid, uid_t uid, bool all_threads); struct thread_map *thread_map__new_by_tid_str(const char *tid_str); -- 2.25.1