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=-11.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 EEB89C43463 for ; Sat, 19 Sep 2020 07:01:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C2FB720866 for ; Sat, 19 Sep 2020 07:01:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726170AbgISHBW (ORCPT ); Sat, 19 Sep 2020 03:01:22 -0400 Received: from verein.lst.de ([213.95.11.211]:35075 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726054AbgISHBW (ORCPT ); Sat, 19 Sep 2020 03:01:22 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 6D18468BEB; Sat, 19 Sep 2020 09:01:17 +0200 (CEST) Date: Sat, 19 Sep 2020 09:01:17 +0200 From: Christoph Hellwig To: Jan Kara Cc: Christoph Hellwig , Jens Axboe , Song Liu , Hans de Goede , Richard Weinberger , Minchan Kim , linux-mtd@lists.infradead.org, dm-devel@redhat.com, linux-block@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, David Sterba Subject: Re: [PATCH 04/12] bdi: initialize ->ra_pages and ->io_pages in bdi_init Message-ID: <20200919070117.GB8237@lst.de> References: <20200910144833.742260-1-hch@lst.de> <20200910144833.742260-5-hch@lst.de> <20200917100459.GK7347@quack2.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200917100459.GK7347@quack2.suse.cz> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org On Thu, Sep 17, 2020 at 12:04:59PM +0200, Jan Kara wrote: > On Thu 10-09-20 16:48:24, Christoph Hellwig wrote: > > Set up a readahead size by default, as very few users have a good > > reason to change it. > > > > Signed-off-by: Christoph Hellwig > > Acked-by: David Sterba [btrfs] > > Acked-by: Richard Weinberger [ubifs, mtd] > > Looks good but what about coda, ecryptfs, and orangefs? Currenly they have > readahead disabled and this patch would seem to enable it? When going through this I pinged all maintainers and asked if anyone had a reason to actually disable the readahead, and only vbox and the mtd/ubifs maintainers came up with a reason. > > > diff --git a/mm/backing-dev.c b/mm/backing-dev.c > > index 8e8b00627bb2d8..2dac3be6127127 100644 > > --- a/mm/backing-dev.c > > +++ b/mm/backing-dev.c > > @@ -746,6 +746,8 @@ struct backing_dev_info *bdi_alloc(int node_id) > > kfree(bdi); > > return NULL; > > } > > + bdi->ra_pages = VM_READAHEAD_PAGES; > > + bdi->io_pages = VM_READAHEAD_PAGES; > > Won't this be more logical in bdi_init() than in bdi_alloc()? bdi_init is also used for noop_backing_dev_info, which should not have readahead enabled. In fact the only caller except for bdi_alloc is the initialization of noop_backing_dev_info.