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=-1.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 9CD34C10F11 for ; Mon, 22 Apr 2019 10:55:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7035F204EC for ; Mon, 22 Apr 2019 10:55:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fQ84+lwr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726790AbfDVKzw (ORCPT ); Mon, 22 Apr 2019 06:55:52 -0400 Received: from mail-wm1-f67.google.com ([209.85.128.67]:36438 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726057AbfDVKzw (ORCPT ); Mon, 22 Apr 2019 06:55:52 -0400 Received: by mail-wm1-f67.google.com with SMTP id h18so14068645wml.1; Mon, 22 Apr 2019 03:55:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:cc:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding; bh=+4ZOEYcLzrMo4ZHcpR3pel+OMyjiYzpLVJphuP5KDLg=; b=fQ84+lwrssrlJ5mKgf9lv8XHOejhTuf0LPXo4d4P96QrPLVK7xpUEwgzeCDke1VK8e xLt4SE1wTlPmuWwZh8zrZhDndYg1tTzsRdg6cLLUKT/z2ov+zLsFJyAC3znzeNoax3XW PlMuJCIBAppGyy486JUxzc72sPrK8r/qNYXysUOp1m+0pzCnUErXgNBsf+QGeWIGI4X6 oOeh8Kw6Z1BbBG2R1+JfJG9uYt6kn38sX59qT9h+RrzJBJPXTI/HL9StaO/oW8MO8Oy4 wMtYkVYnagn4YjO8r+PIxrB3qczf9IvZDtLhx22brzuJMNF7VYWKv0nIttyqbxmX9/dG J23g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:cc:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=+4ZOEYcLzrMo4ZHcpR3pel+OMyjiYzpLVJphuP5KDLg=; b=Vk2MqSjFpS5fXlivGEkLPn4sIWU9DXkLjhnEEIptOeti2555lzu5EoB8ehGTImEcCs BUK3zZ1W/lw+NJ8to5Sht5A8s+0kHcyrXNkd7BD+3nQgnebU4Lj66j8q9pt3okbADy0r W5n2MyleQAjkfxyUxj1oDJ6eENc58k3RjTbNpcPiym91UMrpChxHucUfugCtXxxUkuET tkU38haLF+qwWgWmVfzK8k9yK5qXgqRu+Ij1NAac0O/UX9EipRqOsPZebG1O7iypae2X TJj19BFkiHnEYuciIUGT7d5qWYs19jQLF/lJBBIyZK8V3SriX9fUij48cF0I3ilbUK3M blFA== X-Gm-Message-State: APjAAAWKGPwFGB+H4G5UMlhPrFF9WufKO0PEm3kr+SD6dZZI7uR23wwO zvYtj5PBSx2q23K2PAO0T5mk5g6P X-Google-Smtp-Source: APXvYqx8X9zNLML0PY/i6O87i5neFMnoWLzLuvFEYGij0pp+vYpLlJoqBQz/soY2un9z0ejXOIS3qQ== X-Received: by 2002:a1c:6455:: with SMTP id y82mr12004850wmb.104.1555930550088; Mon, 22 Apr 2019 03:55:50 -0700 (PDT) Received: from [10.0.0.5] (bzq-84-110-213-170.static-ip.bezeqint.net. [84.110.213.170]) by smtp.gmail.com with ESMTPSA id c1sm2972459wrp.69.2019.04.22.03.55.48 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 22 Apr 2019 03:55:49 -0700 (PDT) Subject: Re: [POC][PATCH] xfs: reduce ilock contention on buffered randrw workload To: Jan Kara , Dave Chinner References: <20190404165737.30889-1-amir73il@gmail.com> <20190404211730.GD26298@dastard> <20190407232728.GF26298@dastard> <20190408110322.GA18662@quack2.suse.cz> Cc: Amir Goldstein , "Darrick J . Wong" , Christoph Hellwig , Matthew Wilcox , linux-xfs , linux-fsdevel From: Boaz Harrosh Message-ID: <3e7529e5-cd31-5085-ca20-5ca23115c044@gmail.com> Date: Mon, 22 Apr 2019 13:55:42 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <20190408110322.GA18662@quack2.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 08/04/19 14:03, Jan Kara wrote: <> > Hum, you are right. Ext4 is buggy in this regard. I've fixed the race for > page fault in ea3d7209ca01 "ext4: fix races between page faults and hole > punching" but didn't realize the problem is there for buffered reads as > well. I'll think how we can fix this. Thanks for noticing this! > This is very interesting. Please CC me if you have devised a test for this? For a long time I want to enhance fsstress --verify that each writer always writes the long address it writes to as data (ie. file looks like an increasing long counter) And readers want to see only this pattern or zero. > Honza > Thanks Boaz