From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753200Ab1JTVLq (ORCPT ); Thu, 20 Oct 2011 17:11:46 -0400 Received: from mail-iy0-f174.google.com ([209.85.210.174]:62547 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752669Ab1JTVLp (ORCPT ); Thu, 20 Oct 2011 17:11:45 -0400 Date: Thu, 20 Oct 2011 14:11:40 -0700 From: Tejun Heo To: Vivek Goyal Cc: linux-kernel@vger.kernel.org, jaxboe@fusionio.com Subject: Re: [PATCH 2/2] blk-throttle: Take blkcg->lock while traversing blkcg->policy_list Message-ID: <20111020211140.GY25124@google.com> References: <1319144906-5066-1-git-send-email-vgoyal@redhat.com> <1319144906-5066-2-git-send-email-vgoyal@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1319144906-5066-2-git-send-email-vgoyal@redhat.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Thu, Oct 20, 2011 at 05:08:26PM -0400, Vivek Goyal wrote: > blkcg->policy_list is protected by blkcg->lock. Its not rcu protected > list. So even for readers, they need to take blkcg->lock. There are > few functions which were reading the list without taking lock. Fix it. > > Signed-off-by: Vivek Goyal Acked-by: Tejun Heo And yeap, some of rcu usages in cfq/iocg seem either incorrect or unnecessary. Trying to clean up that now too. Thank you. -- tejun