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=-19.1 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 D4050C433F5 for ; Sat, 4 Sep 2021 15:34:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A675D6054F for ; Sat, 4 Sep 2021 15:34:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231715AbhIDPgA (ORCPT ); Sat, 4 Sep 2021 11:36:00 -0400 Received: from out30-44.freemail.mail.aliyun.com ([115.124.30.44]:40143 "EHLO out30-44.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230312AbhIDPgA (ORCPT ); Sat, 4 Sep 2021 11:36:00 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04423;MF=haoxu@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0UnDBaYc_1630769696; Received: from B-25KNML85-0107.local(mailfrom:haoxu@linux.alibaba.com fp:SMTPD_---0UnDBaYc_1630769696) by smtp.aliyun-inc.com(127.0.0.1); Sat, 04 Sep 2021 23:34:56 +0800 Subject: Re: [PATCH 6/6] io_uring: enable multishot mode for accept To: Jens Axboe Cc: io-uring@vger.kernel.org, Pavel Begunkov , Joseph Qi References: <20210903110049.132958-1-haoxu@linux.alibaba.com> <20210903110049.132958-7-haoxu@linux.alibaba.com> From: Hao Xu Message-ID: <95387504-3986-77df-7cb4-d136dd4be1ec@linux.alibaba.com> Date: Sat, 4 Sep 2021 23:34:55 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 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 2021/9/4 上午12:29, Jens Axboe 写道: > On 9/3/21 5:00 AM, Hao Xu wrote: >> Update io_accept_prep() to enable multishot mode for accept operation. >> >> Signed-off-by: Hao Xu >> --- >> fs/io_uring.c | 14 ++++++++++++-- >> 1 file changed, 12 insertions(+), 2 deletions(-) >> >> diff --git a/fs/io_uring.c b/fs/io_uring.c >> index eb81d37dce78..34612646ae3c 100644 >> --- a/fs/io_uring.c >> +++ b/fs/io_uring.c >> @@ -4861,6 +4861,7 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags) >> static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) >> { >> struct io_accept *accept = &req->accept; >> + bool is_multishot; >> >> if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL)) >> return -EINVAL; >> @@ -4872,14 +4873,23 @@ static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) >> accept->flags = READ_ONCE(sqe->accept_flags); >> accept->nofile = rlimit(RLIMIT_NOFILE); >> >> + is_multishot = accept->flags & IORING_ACCEPT_MULTISHOT; >> + if (is_multishot && (req->flags & REQ_F_FORCE_ASYNC)) >> + return -EINVAL; > > I like the idea itself as I think it makes a lot of sense to just have > an accept sitting there and generating multiple CQEs, but I'm a bit > puzzled by how you pass it in. accept->flags is the accept4(2) flags, > which can currently be: > > SOCK_NONBLOCK > SOCK_CLOEXEC > > While there's not any overlap here, that is mostly by chance I think. A > cleaner separation is needed here, what happens if some other accept4(2) > flag is enabled and it just happens to be the same as > IORING_ACCEPT_MULTISHOT? Make sense, how about a new IOSQE flag, I saw not many entries left there. >