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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 38B8EC4346E for ; Mon, 21 Sep 2020 18:20:05 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D18E7221E2 for ; Mon, 21 Sep 2020 18:20:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D18E7221E2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 24BC89000A7; Mon, 21 Sep 2020 14:20:04 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1FCDC90008B; Mon, 21 Sep 2020 14:20:04 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0E9BE9000A7; Mon, 21 Sep 2020 14:20:04 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0007.hostedemail.com [216.40.44.7]) by kanga.kvack.org (Postfix) with ESMTP id ED7B490008B for ; Mon, 21 Sep 2020 14:20:03 -0400 (EDT) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id A94531DF9 for ; Mon, 21 Sep 2020 18:20:03 +0000 (UTC) X-FDA: 77287882686.02.stove08_41008f727147 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin02.hostedemail.com (Postfix) with ESMTP id 011F81014CA0A for ; Mon, 21 Sep 2020 18:18:44 +0000 (UTC) X-HE-Tag: stove08_41008f727147 X-Filterd-Recvd-Size: 2400 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Mon, 21 Sep 2020 18:18:44 +0000 (UTC) Received: by verein.lst.de (Postfix, from userid 2407) id 259D968B02; Mon, 21 Sep 2020 20:18:42 +0200 (CEST) Date: Mon, 21 Sep 2020 20:18:41 +0200 From: Christoph Hellwig To: Coly Li Cc: Christoph Hellwig , Jens Axboe , Song Liu , Hans de Goede , Richard Weinberger , Minchan Kim , Johannes Thumshirn , Justin Sanders , linux-mtd@lists.infradead.org, dm-devel@redhat.com, linux-block@vger.kernel.org, linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, drbd-dev@lists.linbit.com, linux-raid@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org Subject: Re: [PATCH 03/13] bcache: inherit the optimal I/O size Message-ID: <20200921181841.GB2067@lst.de> References: <20200921080734.452759-1-hch@lst.de> <20200921080734.452759-4-hch@lst.de> <20200921140010.GA14672@lst.de> <5bcc52dc-ca8f-bbdd-69ef-4b6312e7994a@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5bcc52dc-ca8f-bbdd-69ef-4b6312e7994a@suse.de> User-Agent: Mutt/1.5.17 (2007-11-01) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Sep 21, 2020 at 11:09:48PM +0800, Coly Li wrote: > I feel this is something should be fixed. Indeed I overlooked it until > you point out the issue now. > > The optimal request size and read ahead pages hint are necessary, but > current initialization is simple. A better way might be dynamically > setting them depends on the cache mode and some special configuration. > > By your inspiration, I want to ACK your original patch although it > doesn't work fine for all condition. Then we may know these two settings > (ra_pages and queue_io_opt) should be improved for more situations. At > lease for most part of the situations they provide proper hints. > > How do you think of the above idea ? Sounds like a plan. I'd reall like to get this series in to get some soaking before the end of the merge window, but we should still have plenty of time for localized bcache updates.