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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_NEOMUTT autolearn=ham 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 E75BCC0044C for ; Wed, 7 Nov 2018 14:07:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B2EA421019 for ; Wed, 7 Nov 2018 14:07:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B2EA421019 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727845AbeKGXiK (ORCPT ); Wed, 7 Nov 2018 18:38:10 -0500 Received: from mx2.suse.de ([195.135.220.15]:39970 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726635AbeKGXiK (ORCPT ); Wed, 7 Nov 2018 18:38:10 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 0AF42B179; Wed, 7 Nov 2018 14:07:37 +0000 (UTC) Date: Wed, 7 Nov 2018 15:07:36 +0100 From: Petr Mladek To: Tetsuo Handa Cc: Sergey Senozhatsky , Sergey Senozhatsky , Dmitriy Vyukov , Steven Rostedt , Alexander Potapenko , Fengguang Wu , Josh Poimboeuf , LKML , Linus Torvalds , Andrew Morton , linux-mm@kvack.org, Ingo Molnar , Peter Zijlstra , Will Deacon Subject: Re: [PATCH 2/3] mm: Use line-buffered printk() for show_free_areas(). Message-ID: <20181107140736.hmsomid74ofzpxvd@pathway.suse.cz> References: <1541165517-3557-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> <1541165517-3557-2-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1541165517-3557-2-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> User-Agent: NeoMutt/20170421 (1.8.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 2018-11-02 22:31:56, Tetsuo Handa wrote: > syzbot is sometimes getting mixed output like below due to concurrent > printk(). Mitigate such output by using line-buffered printk() API. > > Node 0 DMA: 1*4kB (U) 0*8kB 0*16kB 1*32kB > syz-executor0: page allocation failure: order:0, mode:0x484020(GFP_ATOMIC|__GFP_COMP), nodemask=(null) > (U) > syz-executor0 cpuset= > 2*64kB > syz0 > (U) > mems_allowed=0 > 1*128kB > CPU: 0 PID: 7592 Comm: syz-executor0 Not tainted 4.19.0-rc6+ #118 > (U) > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > 1*256kB (U) > Call Trace: > 0*512kB > > 1*1024kB > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113 > (U) > 1*2048kB > warn_alloc.cold.119+0xb7/0x1bd mm/page_alloc.c:3426 > (M) > > Signed-off-by: Tetsuo Handa > Cc: Andrew Morton > --- > mm/page_alloc.c | 32 +++++++++++++++++--------------- > 1 file changed, 17 insertions(+), 15 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index a919ba5..4411d5a 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -4694,10 +4694,10 @@ unsigned long nr_free_pagecache_pages(void) > return nr_free_zone_pages(gfp_zone(GFP_HIGHUSER_MOVABLE)); > } > > -static inline void show_node(struct zone *zone) > +static inline void show_node(struct zone *zone, struct printk_buffer *buf) > { > if (IS_ENABLED(CONFIG_NUMA)) > - printk("Node %d ", zone_to_nid(zone)); > + printk_buffered(buf, "Node %d ", zone_to_nid(zone)); The conversion looks fine to me. I just think about renaming printk_buffered to bprintk(). Best Regards, Petr