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=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_MUTT 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 C2367C04E84 for ; Tue, 28 May 2019 15:14:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9BB9F2075B for ; Tue, 28 May 2019 15:14:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559056453; bh=Z91UY8dK/AnpjJiSkEhTPKP46FR+/a3ykZKWhTbLDK8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=N3s4o39UuzcQBWyMSa3Rg4vXrWz5wFCye+dFCEZO7HCdvnQPSX3DqgHM7qVjHmL6s TU+PqkRpS1gH1Do06r3PA3Rkzv1MAaMpSnWkpaW47avTZzAjtcwB8THq/SMpS844ey 9RFCJab/C/WvduyN38bCFx/bHlsxjwtbDmHPSMsg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727979AbfE1PON (ORCPT ); Tue, 28 May 2019 11:14:13 -0400 Received: from mx2.suse.de ([195.135.220.15]:48110 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726969AbfE1POL (ORCPT ); Tue, 28 May 2019 11:14:11 -0400 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 0FE26ACE8; Tue, 28 May 2019 15:14:09 +0000 (UTC) Date: Tue, 28 May 2019 17:14:07 +0200 From: Michal Hocko To: Minchan Kim Cc: Andrew Morton , linux-mm , LKML , stable@kernel.org, Wu Fangsuo , Pankaj Suryawanshi Subject: Re: [PATCH] mm: fix trying to reclaim unevicable LRU page Message-ID: <20190528151407.GE1658@dhcp22.suse.cz> References: <20190524071114.74202-1-minchan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190524071114.74202-1-minchan@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [Cc Pankaj Suryawanshi who has reported a similar problem http://lkml.kernel.org/r/SG2PR02MB309806967AE91179CAFEC34BE84B0@SG2PR02MB3098.apcprd02.prod.outlook.com] On Fri 24-05-19 16:11:14, Minchan Kim wrote: > There was below bugreport from Wu Fangsuo. > > 7200 [ 680.491097] c4 7125 (syz-executor) page:ffffffbf02f33b40 count:86 mapcount:84 mapping:ffffffc08fa7a810 index:0x24 > 7201 [ 680.531186] c4 7125 (syz-executor) flags: 0x19040c(referenced|uptodate|arch_1|mappedtodisk|unevictable|mlocked) > 7202 [ 680.544987] c0 7125 (syz-executor) raw: 000000000019040c ffffffc08fa7a810 0000000000000024 0000005600000053 > 7203 [ 680.556162] c0 7125 (syz-executor) raw: ffffffc009b05b20 ffffffc009b05b20 0000000000000000 ffffffc09bf3ee80 > 7204 [ 680.566860] c0 7125 (syz-executor) page dumped because: VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page)) > 7205 [ 680.578038] c0 7125 (syz-executor) page->mem_cgroup:ffffffc09bf3ee80 > 7206 [ 680.585467] c0 7125 (syz-executor) ------------[ cut here ]------------ > 7207 [ 680.592466] c0 7125 (syz-executor) kernel BUG at /home/build/farmland/adroid9.0/kernel/linux/mm/vmscan.c:1350! > 7223 [ 680.603663] c0 7125 (syz-executor) Internal error: Oops - BUG: 0 [#1] PREEMPT SMP > 7224 [ 680.611436] c0 7125 (syz-executor) Modules linked in: > 7225 [ 680.616769] c0 7125 (syz-executor) CPU: 0 PID: 7125 Comm: syz-executor Tainted: G S 4.14.81 #3 > 7226 [ 680.626826] c0 7125 (syz-executor) Hardware name: ASR AQUILAC EVB (DT) > 7227 [ 680.633623] c0 7125 (syz-executor) task: ffffffc00a54cd00 task.stack: ffffffc009b00000 > 7228 [ 680.641917] c0 7125 (syz-executor) PC is at shrink_page_list+0x1998/0x3240 > 7229 [ 680.649144] c0 7125 (syz-executor) LR is at shrink_page_list+0x1998/0x3240 > 7230 [ 680.656303] c0 7125 (syz-executor) pc : [] lr : [] pstate: 60400045 > 7231 [ 680.666086] c0 7125 (syz-executor) sp : ffffffc009b05940 > .. > 7342 [ 681.671308] c0 7125 (syz-executor) [] shrink_page_list+0x1998/0x3240 > 7343 [ 681.679567] c0 7125 (syz-executor) [] reclaim_clean_pages_from_list+0x3c0/0x4f0 > 7344 [ 681.688793] c0 7125 (syz-executor) [] alloc_contig_range+0x3bc/0x650 > 7347 [ 681.717421] c0 7125 (syz-executor) [] cma_alloc+0x214/0x668 > 7348 [ 681.724892] c0 7125 (syz-executor) [] ion_cma_allocate+0x98/0x1d8 > 7349 [ 681.732872] c0 7125 (syz-executor) [] ion_alloc+0x200/0x7e0 > 7350 [ 681.740302] c0 7125 (syz-executor) [] ion_ioctl+0x18c/0x378 > 7351 [ 681.747738] c0 7125 (syz-executor) [] do_vfs_ioctl+0x17c/0x1780 > 7352 [ 681.755514] c0 7125 (syz-executor) [] SyS_ioctl+0xac/0xc0 > > Wu found it's due to [1]. Before that, unevictable page goes to cull_mlocked > routine so that it couldn't reach the VM_BUG_ON_PAGE line. > > To fix the issue, this patch filter out unevictable LRU pages > from the reclaim_clean_pages_from_list in CMA. The changelog is rather modest on details and I have to confess I have little bit hard time to understand it. E.g. why do not we need to handle the regular reclaim path? > [1] ad6b67041a45, mm: remove SWAP_MLOCK in ttu > > Cc: [4.12+] > Reported-debugged-by: Wu Fangsuo > Signed-off-by: Minchan Kim > --- > mm/vmscan.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index d9c3e873eca6..7350afae5c3c 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -1505,7 +1505,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone, > > list_for_each_entry_safe(page, next, page_list, lru) { > if (page_is_file_cache(page) && !PageDirty(page) && > - !__PageMovable(page)) { > + !__PageMovable(page) && !PageUnevictable(page)) { > ClearPageActive(page); > list_move(&page->lru, &clean_pages); > } > -- > 2.22.0.rc1.257.g3120a18244-goog > -- Michal Hocko SUSE Labs