From: Mike Galbraith <efault@gmx.de>
Date: Thu, 29 Jan 2009 13:06:52 +0000 (+0100)
Subject: perfcounters: fix refcounting bug
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=65d370862f64973611a271ced61864b5f9bb6fc0;p=linux-beck.git

perfcounters: fix refcounting bug

don't kfree in use counters.

Running...

	while true; do perfstat -e 1 -c true; done

...on all cores for a while doesn't seem to be eating ram, and my oops
is gone.

Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 1ac18daa424f..f27a7e9f3c41 100644
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -1934,7 +1934,8 @@ __perf_counter_exit_task(struct task_struct *child,
 		}
 	}
 
-	kfree(child_counter);
+	if (!child_counter->filp || !atomic_long_read(&child_counter->filp->f_count))
+		kfree(child_counter);
 }
 
 /*