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=-8.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 C7C18C28CBC for ; Wed, 6 May 2020 14:40:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 963F5208D5 for ; Wed, 6 May 2020 14:40:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="W6vSSifC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728968AbgEFOkL (ORCPT ); Wed, 6 May 2020 10:40:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51712 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726114AbgEFOkK (ORCPT ); Wed, 6 May 2020 10:40:10 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CCA9AC061A0F; Wed, 6 May 2020 07:40:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=SnYKovQQh+r4DAzMjzqORJewlrdpqJX+DVWHWQY+cb8=; b=W6vSSifCrciNYazwbnNzBnzC3E ch7nEwPMDVzXwTnLWrdybTGHFzvboaQu3fxcOXYMNYWlVJg1NKqo62H9dT/6nu9KNW8iAcMPJTepA sYLhgtLwbVvj+nEn6bjMb9eKLIAiPl6Dqw5P3IQY6Gidaw5Wj88FSGlVHLhtQegVEInL1FNrodwRc PrOCzZTMmk0og/sPg23BIqAChOEvp74oKF8yEVtupAjVRdxDdwFScvglGLulCwvJA4HULFW483prG ONVKgaYS5wwK7s8Z7WZnLqWRMVxTInuxTD3lfdDrT6xb2DE+gly8/Zq2lB1+39M1p4w7oJZ3CY6bG qeHespng==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWLDW-0001JC-4f; Wed, 06 May 2020 14:40:10 +0000 Date: Wed, 6 May 2020 07:40:10 -0700 From: Christoph Hellwig To: Konstantin Khlebnikov Cc: Christoph Hellwig , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, Jens Axboe Subject: Re: [PATCH RFC 1/2] fs/iomap/direct-io: pass NOWAIT to bio flags Message-ID: <20200506144010.GA27643@infradead.org> References: <158860769311.32485.8003552176738816448.stgit@buzz> <20200504160052.GA8625@infradead.org> <94ec1b65-5f4c-6b56-5a47-ca186615d978@yandex-team.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <94ec1b65-5f4c-6b56-5a47-ca186615d978@yandex-team.ru> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Mon, May 04, 2020 at 07:23:50PM +0300, Konstantin Khlebnikov wrote: > 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. Once the fio changes land, can you add a simple fio based test to xfstests?