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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=no 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 3D9A6C4363D for ; Fri, 25 Sep 2020 09:19:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D90262072E for ; Fri, 25 Sep 2020 09:19:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727044AbgIYJTE (ORCPT ); Fri, 25 Sep 2020 05:19:04 -0400 Received: from out4436.biz.mail.alibaba.com ([47.88.44.36]:36209 "EHLO out4436.biz.mail.alibaba.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726255AbgIYJTE (ORCPT ); Fri, 25 Sep 2020 05:19:04 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R821e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04426;MF=haoxu@linux.alibaba.com;NM=1;PH=DS;RN=2;SR=0;TI=SMTPD_---0UA0mBEs_1601025532; Received: from B-25KNML85-0107.local(mailfrom:haoxu@linux.alibaba.com fp:SMTPD_---0UA0mBEs_1601025532) by smtp.aliyun-inc.com(127.0.0.1); Fri, 25 Sep 2020 17:18:52 +0800 To: axboe@kernel.dk Cc: io-uring@vger.kernel.org From: Hao_Xu Subject: [Question] about async buffered reads feature Message-ID: Date: Fri, 25 Sep 2020 17:18:52 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.2.2 MIME-Version: 1.0 Content-Type: text/plain; charset=gbk; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Hi Jens, I'm doing tests about this feature: [PATCHSET RFC 0/11] Add support for async buffered reads But currently with fio testing, I found the code doesn't go to the essential places in the function generic_file_buffered_read: if (iocb->ki_flags & IOCB_WAITQ) { if (written) { put_page(page); goto out; } error = wait_on_page_locked_async(page, iocb->ki_waitq); } else { and page_not_up_to_date: /* Get exclusive access to the page ... */ if (iocb->ki_flags & IOCB_WAITQ) error = lock_page_async(page, iocb->ki_waitq); else could you give me a copy of your test program which you mentioned in the RFC? My testing environment: fio version: 3.10 kernel version: the mainline kernel, latest commit is 805c6d3c19210c90c109107d189744e960eae025 Thanks, Hao