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Date: Wed, 01 Sep 2010 17:38:26 +0800
From: Li Zefan <lizf@cn.fujitsu.com>
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To: Avi Kivity <avi@redhat.com>
CC: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@elte.hu>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>, kvm-devel <kvm@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: ftrace/perf_event leak
References: <4C7E11E5.1040402@redhat.com> <1283331868.2059.808.camel@laptop> <4C7E1C36.6070400@redhat.com>
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Avi Kivity wrote:
>  On 09/01/2010 12:04 PM, Peter Zijlstra wrote:
>>
>> Does something like the below cure that?
>>
> 
> Unfortunately not.
> 

Then try this:

The bug should be caused by commit 1c024eca51fdc965290acf342ae16a476c2189d0.

---
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 8a2b73f..9d1d1f2 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -161,6 +161,7 @@ void perf_trace_destroy(struct perf_event *p_event)
 		}
 	}
 out:
+	module_put(tp_event->mod);
 	mutex_unlock(&event_mutex);
 }