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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 5D54AC433DB for ; Mon, 1 Mar 2021 09:09:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 14B6164E01 for ; Mon, 1 Mar 2021 09:09:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233519AbhCAJJx (ORCPT ); Mon, 1 Mar 2021 04:09:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55222 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233372AbhCAJJw (ORCPT ); Mon, 1 Mar 2021 04:09:52 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69443C06174A for ; Mon, 1 Mar 2021 01:09:12 -0800 (PST) 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=RsFljr29JB0nmrWmoePU9o8RBeLqXVI0FzuOhfayKtc=; b=dlwD1aiaI70asikwKO+Xp/4ocQ /ZHuWFPCqoV7nv2TQreuiSgaqoWduf9FqRmZQ5eExUj4a7Xakae6wVF5DfqCZpkQCn/ysRyyqDK4Q cG4ZixffFx5hBdVFPQcahSwCFWpnIEEJfU6W90uH8o/Yo/mZVmBND3DNMFoTfkcfq8xCwsVjP1if0 FE0umKv8ybOsiHszvD7Cq5wc0fB00irAhSWIsApCrKaI0eeSnW43VMEcICrk3Fi+r62UZyCKKS19J hNNrN2nlz9qAn1Q1h1LN1mNWrCbOYuY0W6G0ikvCG+1uqKCQZ0uRGz6bwusH0MmGFaAz5zrf6Tp1b ZMl/SEww==; Received: from hch by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lGeY1-00FWIm-S8; Mon, 01 Mar 2021 09:09:04 +0000 Date: Mon, 1 Mar 2021 09:09:01 +0000 From: Christoph Hellwig To: Dave Chinner Cc: Christoph Hellwig , "Darrick J. Wong" , linux-xfs@vger.kernel.org Subject: Re: [PATCH 2/8] xfs: separate CIL commit record IO Message-ID: <20210301090901.GA3698088@infradead.org> References: <20210223033442.3267258-1-david@fromorbit.com> <20210223033442.3267258-3-david@fromorbit.com> <20210224203429.GR7272@magnolia> <20210224214417.GB4662@dread.disaster.area> <20210225204755.GK4662@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210225204755.GK4662@dread.disaster.area> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org On Fri, Feb 26, 2021 at 07:47:55AM +1100, Dave Chinner wrote: > Sorry, I/O wait might matter for what? Think you have a SAS hard drive, WCE=0, typical queue depth of a few dozend commands. Before that we'd submit a bunch of iclogs, which are generally sequential except of course for the log wrap around case. The drive can now easily take all the iclogs and write them in one rotation. Now if we wait for the previous iclogs before submitting the commit_iclog we need at least one more additional full roundtrip.