Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754562Ab3C2BPa (ORCPT ); Thu, 28 Mar 2013 21:15:30 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:50233 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753811Ab3C2BP3 (ORCPT ); Thu, 28 Mar 2013 21:15:29 -0400 Message-ID: <5154EAE6.6010106@oracle.com> Date: Thu, 28 Mar 2013 21:14:14 -0400 From: Sasha Levin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130310 Thunderbird/17.0.4 MIME-Version: 1.0 To: Michel Lespinasse CC: Rik van Riel , torvalds@linux-foundation.org, davidlohr.bueso@hp.com, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, hhuang@redhat.com, jason.low2@hp.com, lwoodman@redhat.com, chegu_vinod@hp.com, "Paul E. McKenney" Subject: Re: [PATCH -mm -next] ipc,sem: untangle RCU locking with find_alloc_undo References: <1363809337-29718-1-git-send-email-riel@surriel.com> <5151DBD3.6080201@oracle.com> <20130328113222.194bbfe8@cuia.bos.redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1071 Lines: 31 On 03/28/2013 09:00 PM, Michel Lespinasse wrote: > On Thu, Mar 28, 2013 at 8:32 AM, Rik van Riel wrote: >> The ipc semaphore code has a nasty RCU locking tangle, with both >> find_alloc_undo and semtimedop taking the rcu_read_lock(). The >> code can be cleaned up somewhat by only taking the rcu_read_lock >> once. >> >> The only caller of find_alloc_undo is in semtimedop. >> >> This should solve the trinity issue reported by Sasha Levin. >> >> Reported-by: Sasha Levin >> Signed-off-by: Rik van Riel > > Looks good^Wbetter. I have nothing specific to say other than I've > been staring at it for 10 minutes :) > > Reviewed-by: Michel Lespinasse And the warnings are gone: Tested-by: Sasha Levin Thanks, Sasha -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/