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 1FEB3C433E6 for ; Mon, 8 Mar 2021 14:11:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDD1E651E8 for ; Mon, 8 Mar 2021 14:11:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230342AbhCHOLT (ORCPT ); Mon, 8 Mar 2021 09:11:19 -0500 Received: from mx2.suse.de ([195.135.220.15]:38012 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229468AbhCHOLE (ORCPT ); Mon, 8 Mar 2021 09:11:04 -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=1615212663; 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=pbE7xUaOZUpTd375UrFXZhkfFNrYHw34Jke7GnznOGQ=; b=AmEVNKxKn3lR7k0MSGq5MFHlmMPFI8Gsethwq6QHO33ZqkS2gJhixIzGUIZZt6nDeU5wZT Rfu20YmV/uNTcAnq1K8f4lkn+PzD7az7pv/56RQqO9wGviIeAla230+4OHtOAD9cvHVDux oO92keGhrZ4qGLmsJgq135Y+n7VDT2I= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id CE9E3AE15; Mon, 8 Mar 2021 14:11:02 +0000 (UTC) Date: Mon, 8 Mar 2021 15:11:02 +0100 From: Michal Hocko To: David Hildenbrand Cc: Minchan Kim , Andrew Morton , linux-mm , LKML , joaodias@google.com Subject: Re: [PATCH] mm: be more verbose for alloc_contig_range faliures Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 a best effort allocator. Complaining about failure is too noisy. I do agree that some sort of easy to enable debugging is due but please let's make it as transparent to the code as possible. -- Michal Hocko SUSE Labs