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=-16.7 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 6C5CBC4338F for ; Fri, 20 Aug 2021 09:32:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4825D60F44 for ; Fri, 20 Aug 2021 09:32:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233976AbhHTJdI (ORCPT ); Fri, 20 Aug 2021 05:33:08 -0400 Received: from out30-42.freemail.mail.aliyun.com ([115.124.30.42]:50143 "EHLO out30-42.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233148AbhHTJdH (ORCPT ); Fri, 20 Aug 2021 05:33:07 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R311e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04394;MF=haoxu@linux.alibaba.com;NM=1;PH=DS;RN=3;SR=0;TI=SMTPD_---0UkJoTSQ_1629451948; Received: from B-25KNML85-0107.local(mailfrom:haoxu@linux.alibaba.com fp:SMTPD_---0UkJoTSQ_1629451948) by smtp.aliyun-inc.com(127.0.0.1); Fri, 20 Aug 2021 17:32:29 +0800 Subject: Re: [PATCH 1/3] io_uring: flush completions for fallbacks From: Hao Xu To: Pavel Begunkov , Jens Axboe , io-uring@vger.kernel.org References: <8b941516921f72e1a64d58932d671736892d7fff.1629286357.git.asml.silence@gmail.com> Message-ID: <02c3a528-c628-631b-487f-24a989cf1d3d@linux.alibaba.com> Date: Fri, 20 Aug 2021 17:32:28 +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: 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 2021/8/20 下午5:21, Hao Xu 写道: > 在 2021/8/18 下午7:42, Pavel Begunkov 写道: >> io_fallback_req_func() doesn't expect anyone creating inline >> completions, and no one currently does that. Teach the function to flush >> completions preparing for further changes. >> >> Signed-off-by: Pavel Begunkov >> --- >>   fs/io_uring.c | 5 +++++ >>   1 file changed, 5 insertions(+) >> >> diff --git a/fs/io_uring.c b/fs/io_uring.c >> index 3da9f1374612..ba087f395507 100644 >> --- a/fs/io_uring.c >> +++ b/fs/io_uring.c >> @@ -1197,6 +1197,11 @@ static void io_fallback_req_func(struct >> work_struct *work) >>       percpu_ref_get(&ctx->refs); >>       llist_for_each_entry_safe(req, tmp, node, >> io_task_work.fallback_node) >>           req->io_task_work.func(req); >> + >> +    mutex_lock(&ctx->uring_lock); >> +    if (ctx->submit_state.compl_nr) >> +        io_submit_flush_completions(ctx); >> +    mutex_unlock(&ctx->uring_lock); > why do we protect io_submit_flush_completions() with uring_lock, > regarding that it is called in original context. Btw, why not I mean it is in original context before this patch.. > use ctx_flush_and_put() >>       percpu_ref_put(&ctx->refs); >>   } >>