From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754762Ab1KWRGo (ORCPT ); Wed, 23 Nov 2011 12:06:44 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.125]:40278 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753123Ab1KWRGn (ORCPT ); Wed, 23 Nov 2011 12:06:43 -0500 X-Authority-Analysis: v=2.0 cv=KcRQQHkD c=1 sm=0 a=ZycB6UtQUfgMyuk2+PxD7w==:17 a=c8QOUBVbWuQA:10 a=5SG0PmZfjMsA:10 a=IkcTkHD0fZMA:10 a=JHdT3DEE1iB2qg4j26gA:9 a=QEXdDO2ut3YA:10 a=ZycB6UtQUfgMyuk2+PxD7w==:117 X-Cloudmark-Score: 0 X-Originating-IP: 74.67.80.29 Subject: Re: [PATCH 1/2] trace_events_filter: use rcu_assign_pointer() when setting ftrace_event_call->filter From: Steven Rostedt To: Tejun Heo Cc: Frederic Weisbecker , Ingo Molnar , Jiri Olsa , linux-kernel@vger.kernel.org, "Paul E. McKenney" In-Reply-To: <20111123160653.GB25780@google.com> References: <20111123014603.GA19630@google.com> <1322061407.20742.51.camel@frodo> <20111123160653.GB25780@google.com> Content-Type: text/plain; charset="UTF-8" Date: Wed, 23 Nov 2011 12:06:40 -0500 Message-ID: <1322068000.20742.61.camel@frodo> Mime-Version: 1.0 X-Mailer: Evolution 2.32.3 (2.32.3-1.fc14) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2011-11-23 at 08:06 -0800, Tejun Heo wrote: > So, synchronized_sched() being called after isn't relevant. We want > smp_wmb() between data structure initialization and assignment of the > new pointer. Ah, you're saying that we need to guarantee that the allocated filter is seen before we update the call->filter to point to it. OK, fair enough, this does look like a bug fix. Is it big enough to be considered for stable? -- Steve