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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 AD896C43381 for ; Thu, 18 Feb 2021 10:19:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7DFCA64E85 for ; Thu, 18 Feb 2021 10:19:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232588AbhBRKK2 (ORCPT ); Thu, 18 Feb 2021 05:10:28 -0500 Received: from mx2.suse.de ([195.135.220.15]:44214 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231261AbhBRI5F (ORCPT ); Thu, 18 Feb 2021 03:57:05 -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=1613638579; 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=8RAszh7yrqFMBVVaDFUSTwmQ6Tv/ON0s4M9Tz9qKwYg=; b=VeKsaAxMxonW/fD/t12Ia80ScMOR6LGjZl7eGItzFNo4Yxu2+IDqnAMrfmw/FiXSEbHM3f HXfyeiLxxftUjGZRFMCg1ZCaP3LQ1lj+pif3w2fU6YWXwOLXZk9U1HHbsqhKLtpmujbkIK 1GzcAD728DMOsM6asbmcgSVMLoSjEzY= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 740FFAD87; Thu, 18 Feb 2021 08:56:19 +0000 (UTC) Date: Thu, 18 Feb 2021 09:56:18 +0100 From: Michal Hocko To: Minchan Kim Cc: Andrew Morton , linux-mm , LKML , david@redhat.com, joaodias@google.com Subject: Re: [PATCH] mm: be more verbose for alloc_contig_range faliures Message-ID: References: <20210217163603.429062-1-minchan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210217163603.429062-1-minchan@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 17-02-21 08:36:03, Minchan Kim wrote: > alloc_contig_range is usually used on cma area or movable zone. > It's critical if the page migration fails on those areas so > dump more debugging message like memory_hotplug unless user > specifiy __GFP_NOWARN. I agree with David that this has a potential to generate a lot of output and it is not really clear whether it is worth it. Page isolation code already has REPORT_FAILURE mode which currently used only for the memory hotplug because this was just too noisy from the CMA path - d381c54760dc ("mm: only report isolation failures when offlining memory"). Maybe migration failures are less likely to fail but still. Doesn't CMA allocator provide some useful error reporting on its own? [...] > @@ -8736,8 +8747,11 @@ struct page *alloc_contig_pages(unsigned long nr_pages, gfp_t gfp_mask, > * and cause alloc_contig_range() to fail... > */ > spin_unlock_irqrestore(&zone->lock, flags); > + > + if (zone_idx(zone) != ZONE_MOVABLE) > + gfp_flags = gfp_mask | __GFP_NOWARN; Nack to this. Caller shouldn't tweak gfp mask of the caller. If we really want to control the reporting based on __GFP_NOWARN or a lack of it then this has to be under control of the caller. > ret = __alloc_contig_pages(pfn, nr_pages, > - gfp_mask); > + gfp_flags); > if (!ret) > return pfn_to_page(pfn); > spin_lock_irqsave(&zone->lock, flags); > -- > 2.30.0.478.g8a0d178c01-goog > -- Michal Hocko SUSE Labs