From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759320AbbFBOoo (ORCPT ); Tue, 2 Jun 2015 10:44:44 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:36720 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759371AbbFBOoN (ORCPT ); Tue, 2 Jun 2015 10:44:13 -0400 Message-ID: <556DC139.4060805@fb.com> Date: Tue, 2 Jun 2015 08:44:09 -0600 From: Jens Axboe User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Akinobu Mita , Subject: Re: [PATCH 1/2] null_blk: prevent timer handler running on a different CPU where started References: <1433201710-4284-1-git-send-email-akinobu.mita@gmail.com> In-Reply-To: <1433201710-4284-1-git-send-email-akinobu.mita@gmail.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.54.13] X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.14.151,1.0.33,0.0.0000 definitions=2015-06-02_12:2015-06-02,2015-06-02,1970-01-01 signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/01/2015 05:35 PM, Akinobu Mita wrote: > When irqmode=2 (IRQ completion handler is timer), timer handler should > be called on the same CPU where the timer has been started. > > Since completion_queues are per-cpu and the completion handler only > touches completion_queue for local CPU, we need to prevent the handler > from running on a different CPU where the timer has been started. > Otherwise, the IO cannot be completed until another completion handler > is executed on that CPU. Thanks, applied this and 2/2, the latter seems to have been forgotten after our initial discussion about it. -- Jens Axboe