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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 ACF4DC433DF for ; Fri, 21 Aug 2020 06:00:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 71C63207DA for ; Fri, 21 Aug 2020 06:00:38 +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="akR/dH1A" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725268AbgHUGAi (ORCPT ); Fri, 21 Aug 2020 02:00:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49748 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725951AbgHUGAh (ORCPT ); Fri, 21 Aug 2020 02:00:37 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 68CF7C061385; Thu, 20 Aug 2020 23:00:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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=HWB+/2Nt9PlJumw2ZEaPgdNpFexNYVi38bcYSvOU2wU=; b=akR/dH1A9l7PREYPjibZXxeJbz TrcKAjIO6AOtnVfb5cHo3RKx2gWnUbdO5lLIITlStex6gUJgbL6sqMtxHdjMUiCLsIX2rgN61DQ7+ UAdQL9cDNQb7Sd8opb/ZpCj0XKBVhvMmcETK7Hv4PmSrwOZLkZATxZDccz+CpFV6Uf2tDAhtV9gfE gbgOkAylwCl5+4KrLdRVjVjue6PHzzzV2fq0P6U42KJB+lM9rwCliZbw5ELAUb+yXWAOLBsrAh4xM HZHod7MHQzZVAErqRD8kzJRNJQNR8D8XJN/H0efFvmFI3AoOo+EWAvS6smimAc3281j/TV05ukiVg dKRsysew==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1k906E-0008LC-1n; Fri, 21 Aug 2020 06:00:26 +0000 Date: Fri, 21 Aug 2020 07:00:25 +0100 From: Christoph Hellwig To: Ritesh Harjani Cc: Dave Chinner , Anju T Sudhakar , hch@infradead.org, darrick.wong@oracle.com, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, willy@infradead.org Subject: Re: [PATCH] iomap: Fix the write_count in iomap_add_to_ioend(). Message-ID: <20200821060025.GA31091@infradead.org> References: <20200819102841.481461-1-anju@linux.vnet.ibm.com> <20200820231140.GE7941@dread.disaster.area> <20200821044533.BBFD1A405F@d06av23.portsmouth.uk.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200821044533.BBFD1A405F@d06av23.portsmouth.uk.ibm.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Fri, Aug 21, 2020 at 10:15:33AM +0530, Ritesh Harjani wrote: > Please correct me here, but as I see, bio has only these two limits > which it checks for adding page to bio. It doesn't check for limits > of /sys/block//queue/* no? I guess then it could be checked > by block layer below b4 submitting the bio? The bio does not, but the blk-mq code will split the bios when mapping it to requests, take a look at blk_mq_submit_bio and __blk_queue_split. But while the default limits are quite low, they can be increased siginificantly, which tends to help with performance and is often also done by scripts shipped by the distributions. > This issue was first observed while running a fio run on a system with > huge memory. But then here is an easy way we figured out to trigger the > issue almost everytime with loop device on my VM setup. I have provided > all the details on this below. Can you wire this up for xfstests?