From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758244Ab3E1Ksv (ORCPT ); Tue, 28 May 2013 06:48:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33087 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756363Ab3E1Ksu (ORCPT ); Tue, 28 May 2013 06:48:50 -0400 Date: Tue, 28 May 2013 06:48:40 -0400 From: Jeff Layton To: Luis Henriques Cc: Ben Hutchings , linux-kernel@vger.kernel.org, stable@vger.kernel.org, akpm@linux-foundation.org, "Trond Myklebust" Subject: Re: [54/94] sunrpc: clarify comments on rpc_make_runnable Message-ID: <20130528064840.43a9bb43@corrin.poochiereds.net> In-Reply-To: <87ehcrqtdn.fsf@canonical.com> References: <20130528061435.0e1b1cc4@corrin.poochiereds.net> <87ehcrqtdn.fsf@canonical.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 28 May 2013 11:41:08 +0100 Luis Henriques wrote: > Jeff Layton writes: > > > On Tue, 28 May 2013 04:49:53 +0100 > > Ben Hutchings wrote: > > > >> 3.2.46-rc1 review patch. If anyone has any objections, please let me know. > >> > >> ------------------ > >> > >> From: Jeff Layton > >> > >> commit 506026c3ec270e18402f0c9d33fee37482c23861 upstream. > >> > >> rpc_make_runnable is not generally called with the queue lock held, unless > >> it's waking up a task that has been sitting on a waitqueue. This is safe > >> when the task has not entered the FSM yet, but the comments don't really > >> spell this out. > >> > >> Signed-off-by: Jeff Layton > >> Signed-off-by: Trond Myklebust > >> Signed-off-by: Ben Hutchings > >> --- > >> net/sunrpc/sched.c | 5 +++-- > >> 1 file changed, 3 insertions(+), 2 deletions(-) > >> > >> --- a/net/sunrpc/sched.c > >> +++ b/net/sunrpc/sched.c > >> @@ -296,8 +296,9 @@ EXPORT_SYMBOL_GPL(__rpc_wait_for_complet > >> /* > >> * Make an RPC task runnable. > >> * > >> - * Note: If the task is ASYNC, this must be called with > >> - * the spinlock held to protect the wait queue operation. > >> + * Note: If the task is ASYNC, and is being made runnable after sitting on an > >> + * rpc_wait_queue, this must be called with the queue spinlock held to protect > >> + * the wait queue operation. > >> */ > >> static void rpc_make_runnable(struct rpc_task *task) > >> { > >> > > > > Just a comment patch, so this is harmless and I have no objection but > > why pull it into stable? I had always thought stable-kernel-rules.txt > > discouraged taking patches that don't fix real bugs... > > I believe the reason Ben took this patch is actually to provide the > correct context for the next one: > > a3c3cac5d31879cd9ae2de7874dc6544ca704aec, "SUNRPC: Prevent an rpc_task wakeup race" > > So that this is a clean cherry-pick. > > (At least this was the reason I picked it for the 3.5 kernel.) > > Cheers, Ok, that's understandable -- sorry for the noise... Thanks, -- Jeff Layton