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=-9.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 76A2CC433E0 for ; Thu, 30 Jul 2020 02:32:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5366722B42 for ; Thu, 30 Jul 2020 02:32:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726319AbgG3Cca (ORCPT ); Wed, 29 Jul 2020 22:32:30 -0400 Received: from out30-42.freemail.mail.aliyun.com ([115.124.30.42]:55836 "EHLO out30-42.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726342AbgG3Cca (ORCPT ); Wed, 29 Jul 2020 22:32:30 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R611e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01f04397;MF=jiufei.xue@linux.alibaba.com;NM=1;PH=DS;RN=2;SR=0;TI=SMTPD_---0U4C9fmu_1596076345; Received: from ali-186590e05fa3.local(mailfrom:jiufei.xue@linux.alibaba.com fp:SMTPD_---0U4C9fmu_1596076345) by smtp.aliyun-inc.com(127.0.0.1); Thu, 30 Jul 2020 10:32:25 +0800 Subject: Re: [PATCH liburing 1/2] io_uring_enter: add timeout support To: Jens Axboe Cc: io-uring@vger.kernel.org References: <1596017415-39101-1-git-send-email-jiufei.xue@linux.alibaba.com> <1596017415-39101-2-git-send-email-jiufei.xue@linux.alibaba.com> <0f6cdf31-fbec-d447-989d-969bb936838a@kernel.dk> From: Jiufei Xue Message-ID: <0002bd2c-1375-2b95-fe98-41ee0895141e@linux.alibaba.com> Date: Thu, 30 Jul 2020 10:32:25 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <0f6cdf31-fbec-d447-989d-969bb936838a@kernel.dk> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: io-uring-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Hi Jens, On 2020/7/30 上午1:51, Jens Axboe wrote: > On 7/29/20 4:10 AM, Jiufei Xue wrote: >> Kernel can handle timeout when feature IORING_FEAT_GETEVENTS_TIMEOUT >> supported. Add two new interfaces: io_uring_wait_cqes2(), >> io_uring_wait_cqe_timeout2() for applications to use this feature. > > Why add new new interfaces, when the old ones already pass in the > timeout? Surely they could just use this new feature, instead of the > internal timeout, if it's available? > Applications use the old one may not call io_uring_submit() because io_uring_wait_cqes() will do it. So I considered to add a new one. >> diff --git a/src/include/liburing.h b/src/include/liburing.h >> index 0505a4f..6176a63 100644 >> --- a/src/include/liburing.h >> +++ b/src/include/liburing.h >> @@ -56,6 +56,7 @@ struct io_uring { >> struct io_uring_sq sq; >> struct io_uring_cq cq; >> unsigned flags; >> + unsigned features; >> int ring_fd; >> }; > > This breaks the API, as it changes the size of the ring... > Oh, yes, I haven't considering that before. So could I add this feature bit to io_uring.flags. Any suggestion? Thanks, JIufei.