Commit-ID: b32ee9e522f7ba26339856a047cfe9efc0be0ff3 Gitweb: https://git.kernel.org/tip/b32ee9e522f7ba26339856a047cfe9efc0be0ff3 Author: Kan Liang <kan.li...@intel.com> AuthorDate: Fri, 29 Sep 2017 07:47:52 -0700 Committer: Arnaldo Carvalho de Melo <a...@redhat.com> CommitDate: Tue, 3 Oct 2017 09:27:27 -0300
perf tools: Lock to protect namespaces and comm list Add two locks to protect namespaces_list and comm_list. The lock is only needed for multithreaded code, so using mutex wrappers provided by perf tool. Not all the comm_list/namespaces_list accessing are protected, e.g. thread__exec_comm. Because the multithread code for perf top event synthesizing does not touch them. They don't need a lock. Signed-off-by: Kan Liang <kan.li...@intel.com> Acked-by: Jiri Olsa <jo...@kernel.org> Cc: Adrian Hunter <adrian.hun...@intel.com> Cc: Alexei Starovoitov <a...@kernel.org> Cc: Andi Kleen <a...@linux.intel.com> Cc: He Kuang <heku...@huawei.com> Cc: Lukasz Odzioba <lukasz.odzi...@intel.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Wang Nan <wangn...@huawei.com> Link: http://lkml.kernel.org/r/1506696477-146932-2-git-send-email-kan.li...@intel.com Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/util/thread.c | 53 +++++++++++++++++++++++++++++++++++++++++++----- tools/perf/util/thread.h | 3 +++ 2 files changed, 51 insertions(+), 5 deletions(-) diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c index c09bdb5..bf73117 100644 --- a/tools/perf/util/thread.c +++ b/tools/perf/util/thread.c @@ -45,6 +45,8 @@ struct thread *thread__new(pid_t pid, pid_t tid) thread->cpu = -1; INIT_LIST_HEAD(&thread->namespaces_list); INIT_LIST_HEAD(&thread->comm_list); + init_rwsem(&thread->namespaces_lock); + init_rwsem(&thread->comm_lock); comm_str = malloc(32); if (!comm_str) @@ -83,18 +85,26 @@ void thread__delete(struct thread *thread) map_groups__put(thread->mg); thread->mg = NULL; } + down_write(&thread->namespaces_lock); list_for_each_entry_safe(namespaces, tmp_namespaces, &thread->namespaces_list, list) { list_del(&namespaces->list); namespaces__free(namespaces); } + up_write(&thread->namespaces_lock); + + down_write(&thread->comm_lock); list_for_each_entry_safe(comm, tmp_comm, &thread->comm_list, list) { list_del(&comm->list); comm__free(comm); } + up_write(&thread->comm_lock); + unwind__finish_access(thread); nsinfo__zput(thread->nsinfo); + exit_rwsem(&thread->namespaces_lock); + exit_rwsem(&thread->comm_lock); free(thread); } @@ -125,8 +135,8 @@ struct namespaces *thread__namespaces(const struct thread *thread) return list_first_entry(&thread->namespaces_list, struct namespaces, list); } -int thread__set_namespaces(struct thread *thread, u64 timestamp, - struct namespaces_event *event) +static int __thread__set_namespaces(struct thread *thread, u64 timestamp, + struct namespaces_event *event) { struct namespaces *new, *curr = thread__namespaces(thread); @@ -149,6 +159,17 @@ int thread__set_namespaces(struct thread *thread, u64 timestamp, return 0; } +int thread__set_namespaces(struct thread *thread, u64 timestamp, + struct namespaces_event *event) +{ + int ret; + + down_write(&thread->namespaces_lock); + ret = __thread__set_namespaces(thread, timestamp, event); + up_write(&thread->namespaces_lock); + return ret; +} + struct comm *thread__comm(const struct thread *thread) { if (list_empty(&thread->comm_list)) @@ -170,8 +191,8 @@ struct comm *thread__exec_comm(const struct thread *thread) return last; } -int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp, - bool exec) +static int ____thread__set_comm(struct thread *thread, const char *str, + u64 timestamp, bool exec) { struct comm *new, *curr = thread__comm(thread); @@ -195,6 +216,17 @@ int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp, return 0; } +int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp, + bool exec) +{ + int ret; + + down_write(&thread->comm_lock); + ret = ____thread__set_comm(thread, str, timestamp, exec); + up_write(&thread->comm_lock); + return ret; +} + int thread__set_comm_from_proc(struct thread *thread) { char path[64]; @@ -212,7 +244,7 @@ int thread__set_comm_from_proc(struct thread *thread) return err; } -const char *thread__comm_str(const struct thread *thread) +static const char *__thread__comm_str(const struct thread *thread) { const struct comm *comm = thread__comm(thread); @@ -222,6 +254,17 @@ const char *thread__comm_str(const struct thread *thread) return comm__str(comm); } +const char *thread__comm_str(const struct thread *thread) +{ + const char *str; + + down_read((struct rw_semaphore *)&thread->comm_lock); + str = __thread__comm_str(thread); + up_read((struct rw_semaphore *)&thread->comm_lock); + + return str; +} + /* CHECKME: it should probably better return the max comm len from its comm list */ int thread__comm_len(struct thread *thread) { diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h index cb1a5dd..10555d6 100644 --- a/tools/perf/util/thread.h +++ b/tools/perf/util/thread.h @@ -9,6 +9,7 @@ #include "symbol.h" #include <strlist.h> #include <intlist.h> +#include "rwsem.h" struct thread_stack; struct unwind_libunwind_ops; @@ -29,7 +30,9 @@ struct thread { int comm_len; bool dead; /* if set thread has exited */ struct list_head namespaces_list; + struct rw_semaphore namespaces_lock; struct list_head comm_list; + struct rw_semaphore comm_lock; u64 db_id; void *priv;
