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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D6B2C433FE for ; Fri, 25 Mar 2022 16:54:35 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 752D86B0073; Fri, 25 Mar 2022 12:54:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 701796B0074; Fri, 25 Mar 2022 12:54:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5C7906B0075; Fri, 25 Mar 2022 12:54:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.27]) by kanga.kvack.org (Postfix) with ESMTP id 4E1C66B0073 for ; Fri, 25 Mar 2022 12:54:35 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 291FD20055 for ; Fri, 25 Mar 2022 16:54:35 +0000 (UTC) X-FDA: 79283507310.13.C3D0013 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf30.hostedemail.com (Postfix) with ESMTP id 700DE8002D for ; Fri, 25 Mar 2022 16:54:34 +0000 (UTC) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 2C24F210EF; Fri, 25 Mar 2022 16:54:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1648227273; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=zeVrtVyAK7v5KJnvBMeeYBqAbke4hvV/2TV/CFi2Fyo=; b=ZWcfv6fhSzG9V01DcbjPSVu1jSsXsfkHbGDcMsuW6tKQ0tTkx7WHta4XWtRVh9eqh3CzKo dcacjT7rqYbFS7nOV4NGo8p96EUGBr7g1uAzadN0Jyrhcg8c04Ano+vfr1LrdiwrvOrfI8 2Xo6BYPKjUVIytLpSiLhI9GEmxYDVPM= Received: from suse.cz (unknown [10.100.201.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id ED61BA3B94; Fri, 25 Mar 2022 16:54:32 +0000 (UTC) Date: Fri, 25 Mar 2022 17:54:32 +0100 From: Michal Hocko To: Christoph Hellwig Cc: Andrew Morton , Baoquan He , John Donnelly , David Hildenbrand , linux-mm@kvack.org, LKML Subject: Re: [PATCH] dma/pool: do not complain if DMA pool is not allocated Message-ID: References: <20220325122559.14251-1-mhocko@kernel.org> <20220325164856.GA16800@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220325164856.GA16800@lst.de> Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=ZWcfv6fh; spf=pass (imf30.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.28 as permitted sender) smtp.mailfrom=mhocko@suse.com; dmarc=pass (policy=quarantine) header.from=suse.com X-Stat-Signature: kchrwd48jd8jhzi47kc4uy8fna9gfs48 X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 700DE8002D X-HE-Tag: 1648227274-197264 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 Fri 25-03-22 17:48:56, Christoph Hellwig wrote: > On Fri, Mar 25, 2022 at 01:58:42PM +0100, Michal Hocko wrote: > > Dang, I have just realized that I have misread the boot log and it has > > turned out that a674e48c5443 is covering my situation because the > > allocation failure message says: > > > > Node 0 DMA free:0kB boost:0kB min:0kB low:0kB high:0kB reserved_highatomic:0KB active_anon:0kB inactive_anon:0kB active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB present:636kB managed:0kB mlocked:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB > > As in your report is from a kernel that does not have a674e48c5443 > yet? yes. I just mixed up the early boot messages and thought that DMA zone ended up with a single page. That message was saying something else though. > > I thought there are only few pages in the managed by the DMA zone. This > > is still theoretically possible so I think __GFP_NOWARN makes sense here > > but it would require to change the patch description. > > > > Is this really worth it? > > In general I think for kernels where we need the pool and can't allocate > it, a warning is very useful. We just shouldn't spew it when there is > no need for the pool to start with. Well, do we have any way to find that out during early boot? -- Michal Hocko SUSE Labs