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=-7.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,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 295C8C433E0 for ; Mon, 8 Mar 2021 14:14:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF6E864FE3 for ; Mon, 8 Mar 2021 14:14:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229955AbhCHOOB (ORCPT ); Mon, 8 Mar 2021 09:14:01 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:39135 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230124AbhCHONo (ORCPT ); Mon, 8 Mar 2021 09:13:44 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615212823; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vgbBup6Vj344vbeikJWoQwoH+WZLtLaIQQ1FS0zc2MA=; b=EW3wo2cnnyqRZZ2MWzMMfJXuX/hHM6NTj4R9pd76QVI61bYzgsApY9bJscaA2kW6RwAtct rCOBpwPARtG2RcmQ9WJEUkp8k5fILxnCtENFRKKHERyjI26xwlK40emQrjJnDa77lOK/fm iN/F8uIBUEDWK5A2uGqMao6y9LxdYz4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-151-NGWhpdnuNfq0M1wOFgsz6g-1; Mon, 08 Mar 2021 09:13:39 -0500 X-MC-Unique: NGWhpdnuNfq0M1wOFgsz6g-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 09EC9108BD12; Mon, 8 Mar 2021 14:13:38 +0000 (UTC) Received: from [10.36.113.123] (ovpn-113-123.ams2.redhat.com [10.36.113.123]) by smtp.corp.redhat.com (Postfix) with ESMTP id B0C4A60C6E; Mon, 8 Mar 2021 14:13:36 +0000 (UTC) Subject: Re: [PATCH] mm: be more verbose for alloc_contig_range faliures To: Michal Hocko Cc: Minchan Kim , Andrew Morton , linux-mm , LKML , joaodias@google.com References: From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <9f7b4b8a-5317-e382-7f21-01667e017982@redhat.com> Date: Mon, 8 Mar 2021 15:13:35 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08.03.21 15:11, Michal Hocko wrote: > On Mon 08-03-21 14:22:12, David Hildenbrand wrote: >> On 08.03.21 13:49, Michal Hocko wrote: > [...] >>> Earlier in the discussion I have suggested dynamic debugging facility. >>> Documentation/admin-guide/dynamic-debug-howto.rst. Have you tried to >>> look into that direction? >> >> Did you see the previous mail this is based on: >> >> https://lkml.kernel.org/r/YEEUq8ZRn4WyYWVx@google.com >> >> I agree that "nofail" is misleading. Rather something like >> "dump_on_failure", just a better name :) > > Yeah, I have read through the email thread. I just do not get why we > cannot make it pr_debug() and add -DDYNAMIC_DEBUG_MODULE for > page_alloc.c (I haven't checked whether that is possible for built in > compile units, maybe it is not but from a quick seems it should). > > I really do not like this to be a part of the API. alloc_contig_range is Which API? It does not affect alloc_contig_range() itself, it's used internally only. Sure, we could simply pr_debug() for each and every migration failure. As long as it's default-disabled, sure. I do agree that we should look into properly including this into the dynamic debugging ifrastructure. -- Thanks, David / dhildenb