Received: by 2002:ac0:a5a6:0:0:0:0:0 with SMTP id m35-v6csp3725834imm; Wed, 5 Sep 2018 05:09:17 -0700 (PDT) X-Google-Smtp-Source: ANB0VdbCjaXEYqM4Cg6RbCn8LKJAXeRDRRumbkADAb5YZk1eegXRnphyiDgGH0USA0nCaSAbQgrx X-Received: by 2002:a63:1245:: with SMTP id 5-v6mr27065572pgs.299.1536149356971; Wed, 05 Sep 2018 05:09:16 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1536149356; cv=none; d=google.com; s=arc-20160816; b=znEPN7/mBx/5QwB/hSKGx0Ub9gSDZL5yPfCcY5c1mbL9rr8zgRoCzrrhBESz9v1Twg DzS3T8mEIwrr8g7qauFY3ocmgLdiivcfeXyGtd2Hv0oPZZjBofyd/M+UN16g1FZwk6hg 59dX4TJTxEGMZyBII2Tr4nOo0JvE6ycul9facGdMRgMicLShZw60IcvbV96TPd9nq16V ucYFNkt4IflVbjkhOLkCSIejEJxbkv87u/ShgHN5QVtnNl6MHleLXSuHhS1Bz/prz0vo PWDVBjUAHQlbzpaUv8eUfeAQk65NZp+y+2fcvfcaKF61r5bgFHp37IBunTo80wBUcVxu WP9g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:user-agent:organization:in-reply-to :content-disposition:mime-version:references:message-id:subject:cc :to:from:date; bh=71l0K6BBpBF+SF51xqICaS2y9Z5ZjfP38Eg5Gg/2dHo=; b=BoOOKK1o6uRIB+oonRyWqUcMMyYAaJQnFlplaCMi1iauWKS2EXITzHL7/sKBl6ZMSH bSgb06Q+u2QeDCbBHK/oBgC9bSkuQZywZ6ZjaUdm7LKnBFN+8ntF0DswYIVcUq6lucI0 EcHJJ+9ShDem3pA1sYqUxKVsC3wtR7n8amuKnmJE3X7CwUhrsemCxglpiSrKY2RWlic+ u4c3H7hYAqsqj8i95jncqxZMoM5Ov1VsdDjFesXpguc9H+fwxBjQbORl7OknQ9lwDwph e+WW7Ceewu+gHHpnim4TNw0Aoep3Lj5cml7VyexjSQRzlO+llb0oVpnFj36U9ryer8Dx wVrA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id f12-v6si1807694pgg.653.2018.09.05.05.09.01; Wed, 05 Sep 2018 05:09:16 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727660AbeIEQho (ORCPT + 99 others); Wed, 5 Sep 2018 12:37:44 -0400 Received: from cust-95-128-94-82.breedbanddelft.nl ([95.128.94.82]:50784 "EHLO cust-95-128-94-82.breedbanddelft.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727311AbeIEQhn (ORCPT ); Wed, 5 Sep 2018 12:37:43 -0400 Received: by abra2.bitwizard.nl (Postfix, from userid 1000) id 15BF013F6ED; Wed, 5 Sep 2018 14:07:46 +0200 (CEST) Date: Wed, 5 Sep 2018 14:07:46 +0200 From: Rogier Wolff To: Jeff Layton Cc: =?utf-8?B?54Sm5pmT5Yas?= , bfields@fieldses.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: POSIX violation by writeback error Message-ID: <20180905120745.GP17123@BitWizard.nl> References: <82ffc434137c2ca47a8edefbe7007f5cbecd1cca.camel@redhat.com> <20180904161203.GD17478@fieldses.org> <20180904162348.GN17123@BitWizard.nl> <20180904185411.GA22166@fieldses.org> <09ba078797a1327713e5c2d3111641246451c06e.camel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <09ba078797a1327713e5c2d3111641246451c06e.camel@redhat.com> Organization: BitWizard B.V. User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 05, 2018 at 06:55:15AM -0400, Jeff Layton wrote: > There is no requirement for a filesystem to flush data on close(). And you can't start doing things like that. In some weird cases, you might have an application open-write-close files at a much higher rate than what a harddisk can handle. And this has worked for years because the kernel caches stuff from inodes and data-blocks. If you suddenly write stuff to harddisk at 10ms for each seek between inode area and data-area... You end up limited to about 50 of these open-write-close cycles per second. My home system is now able make/write/close about 100000 files per second. assurancetourix:~/testfiles> time ../a.out 100000 000 0.103u 0.999s 0:01.10 99.0% 0+0k 0+800000io 0pf+0w (The test program was accessing arguments beyond the end-of-arguments, An extra argument for this one time program was easier than open/fix/recompile). Roger. -- ** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2600998 ** ** Delftechpark 26 2628 XH Delft, The Netherlands. KVK: 27239233 ** *-- BitWizard writes Linux device drivers for any device you may have! --* The plan was simple, like my brother-in-law Phil. But unlike Phil, this plan just might work.