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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B712CC433EF for ; Thu, 14 Oct 2021 07:33:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 950C861108 for ; Thu, 14 Oct 2021 07:33:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230054AbhJNHgA (ORCPT ); Thu, 14 Oct 2021 03:36:00 -0400 Received: from mail.itouring.de ([85.10.202.141]:46068 "EHLO mail.itouring.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230020AbhJNHf7 (ORCPT ); Thu, 14 Oct 2021 03:35:59 -0400 Received: from tux.applied-asynchrony.com (p5ddd741d.dip0.t-ipconnect.de [93.221.116.29]) by mail.itouring.de (Postfix) with ESMTPSA id 52EEF8F; Thu, 14 Oct 2021 09:33:54 +0200 (CEST) Received: from tux.applied-asynchrony.com (tux.applied-asynchrony.com [192.168.100.222]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by tux.applied-asynchrony.com (Postfix) with ESMTPS id F1AD2F01604; Thu, 14 Oct 2021 09:33:53 +0200 (CEST) Date: Thu, 14 Oct 2021 09:33:53 +0200 (CEST) From: =?ISO-8859-15?Q?Holger_Hoffst=E4tte?= To: Dave Chinner cc: linux-xfs Subject: Re: Sorting blocks in xfs_buf_delwri_submit_buffers() still necessary? In-Reply-To: <20211013205755.GJ2361455@dread.disaster.area> Message-ID: References: <05c69404-cc05-444b-e4b0-1e358deae272@applied-asynchrony.com> <20211013205755.GJ2361455@dread.disaster.area> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="-1463755164-1744602348-1634196833=:6058" Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. ---1463755164-1744602348-1634196833=:6058 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8BIT On Thu, 14 Oct 2021, Dave Chinner wrote: > On Wed, Oct 13, 2021 at 07:13:10PM +0200, Holger Hoffstätte wrote: >> Hi, >> >> Based on what's going on in blk-mq & NVMe land > > What's going on in this area that is any different from the past few > years? Nothing in particular, just watching Jens pull out all the stops is interesting, and all sorts of other overheads are peeking out from under the couch. >> I though I'd check if XFS still >> sorts buffers before sending them down the pipe, and sure enough that still >> happens in xfs_buf.c:xfs_buf_delwri_submit_buffers() (the comparson function >> is directly above). Before I make a fool of myself and try to remove this, >> do we still think this is necessary? > > Yes, I do. Ok - I completely forgot about merging adjacent requests, and that only works if they are somehow sorted. Makes sense. Thank you for the explanation! Holger ---1463755164-1744602348-1634196833=:6058--