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 <yao....@linux.intel.com> --- tools/perf/util/evlist.c | 2 +- tools/perf/util/thread_map.c | 4 ++-- tools/perf/util/thread_map.h | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 120efd8..9dff74a 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -1106,7 +1106,7 @@ int perf_evlist__create_maps(struct perf_evlist *evlist, struct target *target) struct thread_map *threads; threads = thread_map__new_str(target->pid, target->tid, target->uid, - target->per_thread); + target->per_thread && target->system_wide); if (!threads) return -1; diff --git a/tools/perf/util/thread_map.c b/tools/perf/util/thread_map.c index 3e1038f..729dad8 100644 --- a/tools/perf/util/thread_map.c +++ b/tools/perf/util/thread_map.c @@ -323,7 +323,7 @@ struct thread_map *thread_map__new_by_tid_str(const char *tid_str) } 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 0a806b9..5ec91cf 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); -- 2.7.4