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=-10.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 3D613C47257 for ; Mon, 4 May 2020 16:23:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 148172073B for ; Mon, 4 May 2020 16:23:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=yandex-team.ru header.i=@yandex-team.ru header.b="zt4m8qjE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729601AbgEDQXz (ORCPT ); Mon, 4 May 2020 12:23:55 -0400 Received: from forwardcorp1o.mail.yandex.net ([95.108.205.193]:48398 "EHLO forwardcorp1o.mail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728158AbgEDQXz (ORCPT ); Mon, 4 May 2020 12:23:55 -0400 Received: from mxbackcorp1o.mail.yandex.net (mxbackcorp1o.mail.yandex.net [IPv6:2a02:6b8:0:1a2d::301]) by forwardcorp1o.mail.yandex.net (Yandex) with ESMTP id 5F9BF2E0B11; Mon, 4 May 2020 19:23:52 +0300 (MSK) Received: from iva4-7c3d9abce76c.qloud-c.yandex.net (iva4-7c3d9abce76c.qloud-c.yandex.net [2a02:6b8:c0c:4e8e:0:640:7c3d:9abc]) by mxbackcorp1o.mail.yandex.net (mxbackcorp/Yandex) with ESMTP id jZLbaWK4CF-NpbW5JEh; Mon, 04 May 2020 19:23:52 +0300 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1588609432; bh=no6TW68O+atJXPBJd9FkxYcBR+RL32lyRAIoHBava80=; h=In-Reply-To:Message-ID:From:Date:References:To:Subject:Cc; b=zt4m8qjEBFXYYgR7FHl3xaXs0x6JYyFGFIdvDGK0YYRJyp7DnQmBeKyP7Z3UsNg5h 8BPAJcBiULiqqB6agjJ/F3rkeoBeg2MpWa4p5UfEWfhZ5Et2MoPa9yGPUjvlPNSLCi XpEWUZlpousukGejujQgcf3mX9lAMHFcPYWDIkO8= Authentication-Results: mxbackcorp1o.mail.yandex.net; dkim=pass header.i=@yandex-team.ru Received: from dynamic-vpn.dhcp.yndx.net (dynamic-vpn.dhcp.yndx.net [2a02:6b8:b081:409::1:8]) by iva4-7c3d9abce76c.qloud-c.yandex.net (smtpcorp/Yandex) with ESMTPSA id c71R8gaCcF-NpW8weO5; Mon, 04 May 2020 19:23:51 +0300 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (Client certificate not present) Subject: Re: [PATCH RFC 1/2] fs/iomap/direct-io: pass NOWAIT to bio flags To: Christoph Hellwig Cc: linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Jens Axboe References: <158860769311.32485.8003552176738816448.stgit@buzz> <20200504160052.GA8625@infradead.org> From: Konstantin Khlebnikov Message-ID: <94ec1b65-5f4c-6b56-5a47-ca186615d978@yandex-team.ru> Date: Mon, 4 May 2020 19:23:50 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200504160052.GA8625@infradead.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-CA Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/05/2020 19.00, Christoph Hellwig wrote: > On Mon, May 04, 2020 at 06:54:53PM +0300, Konstantin Khlebnikov wrote: >> This is required to avoid waiting in lower layers. >> >> Signed-off-by: Konstantin Khlebnikov > > This looks sensible. Did you run this through xfstests? > Nope. It seems xfstests has one trivial test for NOWAIT - generic/471 It tests only write with/without extent, nothing about contention. I've added nowait into fio and played with it a little. https://github.com/axboe/fio/pull/972 With these patches I see EAGAINs when queue is flooded.