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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 BF265C433E6 for ; Wed, 10 Mar 2021 13:27:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2F05264FDC for ; Wed, 10 Mar 2021 13:27:13 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2F05264FDC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 902D68D01AD; Wed, 10 Mar 2021 08:27:12 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8B1D18D01A6; Wed, 10 Mar 2021 08:27:12 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 754EE8D01AD; Wed, 10 Mar 2021 08:27:12 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0136.hostedemail.com [216.40.44.136]) by kanga.kvack.org (Postfix) with ESMTP id 598188D01A6 for ; Wed, 10 Mar 2021 08:27:12 -0500 (EST) Received: from smtpin05.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 078B682499A8 for ; Wed, 10 Mar 2021 13:27:12 +0000 (UTC) X-FDA: 77904040704.05.82D0D64 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf10.hostedemail.com (Postfix) with ESMTP id D6D024080F5B for ; Wed, 10 Mar 2021 13:27:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Zd0X1/aQ77xgvEzE/yl2zByaLdoARlJJkbsOi2BArjM=; b=c1XaZJ3ZEQ5d8H/VftDRyxonGI FvAVnhRLizbneVLs0ai09N7WsiHslyr0odSp4KG77tDK+ewYaji6iN21DVlSitvvs5DyxgytRad10 oTUGNipAXr5xIKxl4eKkgh2e2QzQ3KRCt9/aUrlBQK1/MWltaqsMxAOPltwtUKVMiXeD9emq5AtY4 8ncO1thlNgpQ8CW8WvCCt7GrCGn8sNA3FUYJBuH2G8pkwIrFI9NufDaYLncmQGbdVcdEFsHsU/jvA 6IlIyLAN+Odfbe0yAwtgzmCkvxf+BQZT4dgYWFuLFQS77YAZnBIi4c/5EZbFsdtnaCTErbjLEIrLA V5fbFfSA==; Received: from willy by casper.infradead.org with local (Exim 4.94 #2 (Red Hat Linux)) id 1lJyr1-003WfB-5H; Wed, 10 Mar 2021 13:26:29 +0000 Date: Wed, 10 Mar 2021 13:26:23 +0000 From: Matthew Wilcox To: Michal Hocko Cc: Minchan Kim , Andrew Morton , linux-mm , LKML , John Dias , David Hildenbrand , Jason Baron Subject: Re: [PATCH v2] mm: page_alloc: dump migrate-failed pages Message-ID: <20210310132623.GO3479805@casper.infradead.org> References: <20210308202047.1903802-1-minchan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Stat-Signature: n15wzuxh68n71zbn7jybemirto47o1ec X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: D6D024080F5B Received-SPF: none (infradead.org>: No applicable sender policy available) receiver=imf10; identity=mailfrom; envelope-from=""; helo=casper.infradead.org; client-ip=90.155.50.34 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1615382827-286292 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 Tue, Mar 09, 2021 at 10:32:51AM +0100, Michal Hocko wrote: > Apart from the above, do we have to warn for something that is a > debugging aid? A similar concern wrt dump_page which uses pr_warn and > page owner is using even pr_alert. > Would it make sense to add a loglevel parameter both into __dump_page > and dump_page_owner? No. What would make sense is turning __dump_page() inside-out. Something like printk("%pP\n"); In lib/vsprintf.c, there's a big switch statement in the function pointer() that handles printing things like IPv6 addresses, dentries, and function symbols. Then we can do whatever we want around the new %pP, including choosing the log level, adding additional information, choosing to dump the page to a sysfs file, etc, etc.