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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2009-05-15 20:45:59 +0200
committerIngo Molnar <mingo@elte.hu>2009-05-17 07:52:24 +0200
commit856d56b9e5de650a64a6c41c17aaed702b55d578 (patch)
treeaf2fcfe19f0ab27fa220216285e4703ecc7887e1
parent8bc2095951517e2c74b8aeeca4685ddd6b16ed4b (diff)
perf_counter: Fix counter inheritance
Srivatsa Vaddagiri reported that a Java workload triggers this warning in kernel/exit.c: WARN_ON_ONCE(!list_empty(&tsk->perf_counter_ctx.counter_list)); Add the inherited counter propagation on self-detach, this could cause counter leaks and incomplete stats in threaded code like the below: #include <pthread.h> #include <unistd.h> void *thread(void *arg) { sleep(5); return NULL; } void main(void) { pthread_t thr; pthread_create(&thr, NULL, thread, NULL); } Reported-by: Srivatsa Vaddagiri <vatsa@in.ibm.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--kernel/exit.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index 4741376c8de..16d74f13a3e 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -128,6 +128,12 @@ static void __exit_signal(struct task_struct *tsk)
sig = NULL; /* Marker for below. */
}
+ /*
+ * Flush inherited counters to the parent - before the parent
+ * gets woken up by child-exit notifications.
+ */
+ perf_counter_exit_task(tsk);
+
__unhash_process(tsk);
/*