From e1ed3a5b87ed6759e16ec93f16aae83d2cc77ca2 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Tue, 7 Apr 2015 11:59:50 -0300 Subject: [PATCH] perf tools: Use atomic_t to implement thread__{get,put} refcnt Fixing bugs in 'perf top' where the used thread unsafe 'struct thread' refcount implementation was falling apart because we really use two threads. Acked-by: David Ahern Cc: Adrian Hunter Cc: Borislav Petkov Cc: Don Zickus Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Namhyung Kim Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-hil2hol294u5ntcuof4jhmn6@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/thread.c | 6 +++--- tools/perf/util/thread.h | 3 ++- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c index 1c8fbc9..1b26552 100644 --- a/tools/perf/util/thread.c +++ b/tools/perf/util/thread.c @@ -53,7 +53,7 @@ struct thread *thread__new(pid_t pid, pid_t tid) goto err_thread; list_add(&comm->list, &thread->comm_list); - + atomic_set(&thread->refcnt, 0); } return thread; @@ -84,13 +84,13 @@ void thread__delete(struct thread *thread) struct thread *thread__get(struct thread *thread) { - ++thread->refcnt; + atomic_inc(&thread->refcnt); return thread; } void thread__put(struct thread *thread) { - if (thread && --thread->refcnt == 0) { + if (thread && atomic_dec_and_test(&thread->refcnt)) { list_del_init(&thread->node); thread__delete(thread); } diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h index 9b8a54d..f33c48c 100644 --- a/tools/perf/util/thread.h +++ b/tools/perf/util/thread.h @@ -1,6 +1,7 @@ #ifndef __PERF_THREAD_H #define __PERF_THREAD_H +#include #include #include #include @@ -21,7 +22,7 @@ struct thread { pid_t tid; pid_t ppid; int cpu; - int refcnt; + atomic_t refcnt; char shortname[3]; bool comm_set; bool dead; /* if set thread has exited */ -- 2.7.4