From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9E4ACC4338F for ; Wed, 18 Aug 2021 09:22:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A48C60F39 for ; Wed, 18 Aug 2021 09:22:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232203AbhHRJXQ (ORCPT ); Wed, 18 Aug 2021 05:23:16 -0400 Received: from out30-54.freemail.mail.aliyun.com ([115.124.30.54]:37980 "EHLO out30-54.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232634AbhHRJXN (ORCPT ); Wed, 18 Aug 2021 05:23:13 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R491e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01424;MF=haoxu@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0Ujhx.oq_1629278557; Received: from B-25KNML85-0107.local(mailfrom:haoxu@linux.alibaba.com fp:SMTPD_---0Ujhx.oq_1629278557) by smtp.aliyun-inc.com(127.0.0.1); Wed, 18 Aug 2021 17:22:38 +0800 Subject: Re: [PATCH for-5.15] io-wq: move nr_running and worker_refs out of wqe->lock protection From: Hao Xu To: Jens Axboe Cc: io-uring@vger.kernel.org, Pavel Begunkov , Joseph Qi References: <20210810125554.99229-1-haoxu@linux.alibaba.com> Message-ID: Date: Wed, 18 Aug 2021 17:22:37 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: <20210810125554.99229-1-haoxu@linux.alibaba.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org 在 2021/8/10 下午8:55, Hao Xu 写道: ping > We don't need to protect nr_running and worker_refs by wqe->lock, so > narrow the range of raw_spin_lock_irq - raw_spin_unlock_irq > > Signed-off-by: Hao Xu > --- > fs/io-wq.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/fs/io-wq.c b/fs/io-wq.c > index 4ce83bb48021..8da9bb103916 100644 > --- a/fs/io-wq.c > +++ b/fs/io-wq.c > @@ -256,16 +256,17 @@ static void io_wqe_wake_worker(struct io_wqe *wqe, struct io_wqe_acct *acct) > > raw_spin_lock_irq(&wqe->lock); > if (acct->nr_workers < acct->max_workers) { > - atomic_inc(&acct->nr_running); > - atomic_inc(&wqe->wq->worker_refs); > if (!acct->nr_workers) > first = true; > acct->nr_workers++; > do_create = true; > } > raw_spin_unlock_irq(&wqe->lock); > - if (do_create) > + if (do_create) { > + atomic_inc(&acct->nr_running); > + atomic_inc(&wqe->wq->worker_refs); > create_io_worker(wqe->wq, wqe, acct->index, first); > + } > } > } > >