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 CB926C4332B for ; Tue, 26 Jan 2021 06:16:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A3CAE23117 for ; Tue, 26 Jan 2021 06:16:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731657AbhAZGQB (ORCPT ); Tue, 26 Jan 2021 01:16:01 -0500 Received: from mx2.suse.de ([195.135.220.15]:39356 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728695AbhAYNOq (ORCPT ); Mon, 25 Jan 2021 08:14:46 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1611580439; 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=7zbTf32j7jMLRjz7k4qqgBWOWfbhentXzXq3eH/8LBY=; b=mKHBS37s2+sA7ZOhGs+LlrMwEdP9xbrRHfofGjXnCEwGWPMQJGOvfWMLJZDmZvZiUoKvyv eT1iJBEWSCj2vzOH3leLbpb5xhbe2WDB6SkG8Cnob9l4DvHge853kBNjKiUZOUQliLjBrL xr30V0MqeFAckJNk9sftScYmSQlId2s= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 56D5EAAC6; Mon, 25 Jan 2021 13:13:59 +0000 (UTC) Date: Mon, 25 Jan 2021 14:13:43 +0100 From: Michal Hocko To: Minchan Kim Cc: Andrew Morton , linux-mm , LKML , hyesoo.yu@samsung.com, david@redhat.com, surenb@google.com, pullip.cho@samsung.com, joaodias@google.com, hridya@google.com, john.stultz@linaro.org, sumit.semwal@linaro.org, linux-media@vger.kernel.org, devicetree@vger.kernel.org, hch@infradead.org, robh+dt@kernel.org, linaro-mm-sig@lists.linaro.org Subject: Re: [PATCH v4 2/4] mm: failfast mode with __GFP_NORETRY in alloc_contig_range Message-ID: <20210125131343.GH827@dhcp22.suse.cz> References: <20210121175502.274391-1-minchan@kernel.org> <20210121175502.274391-3-minchan@kernel.org> <20210125131200.GG827@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210125131200.GG827@dhcp22.suse.cz> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 25-01-21 14:12:02, Michal Hocko wrote: > On Thu 21-01-21 09:55:00, Minchan Kim wrote: > > Contiguous memory allocation can be stalled due to waiting > > on page writeback and/or page lock which causes unpredictable > > delay. It's a unavoidable cost for the requestor to get *big* > > contiguous memory but it's expensive for *small* contiguous > > memory(e.g., order-4) because caller could retry the request > > in different range where would have easy migratable pages > > without stalling. > > > > This patch introduce __GFP_NORETRY as compaction gfp_mask in > > alloc_contig_range so it will fail fast without blocking > > when it encounters pages needed waiting. > > I am not against controling how hard this allocator tries with gfp mask > but this changelog is rather void on any data and any user. OK, I can see that a user is in the last patch. -- Michal Hocko SUSE Labs