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, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 DC33DC43381 for ; Tue, 26 Mar 2019 09:33:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ACF0320857 for ; Tue, 26 Mar 2019 09:33:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=epicgames-com.20150623.gappssmtp.com header.i=@epicgames-com.20150623.gappssmtp.com header.b="yQ3oxLWA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731273AbfCZJd2 (ORCPT ); Tue, 26 Mar 2019 05:33:28 -0400 Received: from mail-ed1-f65.google.com ([209.85.208.65]:42127 "EHLO mail-ed1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731252AbfCZJd2 (ORCPT ); Tue, 26 Mar 2019 05:33:28 -0400 Received: by mail-ed1-f65.google.com with SMTP id x61so4442806edc.9 for ; Tue, 26 Mar 2019 02:33:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=epicgames-com.20150623.gappssmtp.com; s=20150623; h=mime-version:from:date:message-id:subject:to:cc; bh=1xSRUEM1UhnUDL7ifjfi8Jjv8fd2PXOQZ0AyKG0addE=; b=yQ3oxLWALiJCipF0GvP1A3v301Cr5cKfVnOHiU9bCcm55l70sPFpkkiuSesAaRDlD7 +v1SrrZ3nZJAg4tfjgo0mWhvwlQD9QEY+KjGqgA+0TrgIKuSQndIA1I6P2S/ivlQIH4A TsaKqNtVBSo7TDc5hDyIyVYEzlQesoMXBC3Br0L9TlHPnvH6jWU83PPll+RsvH0KZf+l MctCPK91vV1J89TtnbowgT5w1RyFthj3VEMq9qJ0auxi6jyWGNREis3kxK1ldSHYyVQt HIkhmAchZXzZ7SooGsyRZdA6hgDgPF/JTR8NuYHKeEjvDg5i7aPT1rWCXqX1gZx+Atqe gMsQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to:cc; bh=1xSRUEM1UhnUDL7ifjfi8Jjv8fd2PXOQZ0AyKG0addE=; b=TWBpuMCm5Yq+ZgIe2KNru1HHyZ4pZQwd/uOhHNAVk9F06b1NacEBIHq0jhzMoZWusT ZpfTAjaGtYfLwhWeX+4SN9yBAHwlRkKCHJMch+bc1BhM7kncKD0/lmRE5J4GphvHL28x r0HTS7xvQud5dMaoX5IB2s6A+T61+xbAP2zzPhS1ZuG14cedVQJgCduebnj8Lckbve6W gHhxZYq18960v310KsGeGaMGwMbK8HcLmTQlkaHt34qm6kCFjJeR+JftjUS4kqiP2V1f 6xyi6W3bfK8HKRlJdGyzV2/a0ltM2HJMGOBVk9y5clkMtiY0tPVhrW9AF1x/DtNpyerG joSw== X-Gm-Message-State: APjAAAVSqGzaZaZsUaO2/2Tsk6qgUWaNP9tf86+uQSzDiNaMyrrXo9NE dmMWF5DOWXGYRO8UieEssjoiB5pjC5TX3LDXfzdlOA== X-Google-Smtp-Source: APXvYqyyC9FrUhRbvI2hf6pjbBPurhgQcXAwHEXTklcsk1i66PJDL96Ag6Sq29fpllknZQ19O3k6SS0AC1xMoOSqIpU= X-Received: by 2002:a17:906:68c2:: with SMTP id y2mr1923027ejr.30.1553592806281; Tue, 26 Mar 2019 02:33:26 -0700 (PDT) MIME-Version: 1.0 From: Gavin Will Date: Tue, 26 Mar 2019 09:33:15 +0000 Message-ID: Subject: Re: [PATCH] writeback: fix range_cyclic writeback vs writepages deadlock To: david@fromorbit.com Cc: akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hi We believe we have seen this deadlock issue on our XFS system and currently are trying the patch (aware of the disclaimer that it may not be production ready). However trying to repo this issue is very hard. I was interested in Dave Chinner saying that he had seen a repeatable deadlock and hoped that meant that there was either a process or method that could provoke this situation from happening. Currently we see this deadlock happen about once every 1-2 months and hence trying to speed the iteration up. Regards Gavin Will