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=-0.6 required=3.0 tests=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 A58F7C433DF for ; Mon, 8 Jun 2020 11:44:50 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6229B2074B for ; Mon, 8 Jun 2020 11:44:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="qnfCPEAo" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6229B2074B 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 0AA2F6B0006; Mon, 8 Jun 2020 07:44:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 080F26B0007; Mon, 8 Jun 2020 07:44:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F01156B0008; Mon, 8 Jun 2020 07:44:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0161.hostedemail.com [216.40.44.161]) by kanga.kvack.org (Postfix) with ESMTP id D54326B0006 for ; Mon, 8 Jun 2020 07:44:49 -0400 (EDT) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 9AEC033D58 for ; Mon, 8 Jun 2020 11:44:49 +0000 (UTC) X-FDA: 76905862698.22.key41_5208a2d26db9 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin22.hostedemail.com (Postfix) with ESMTP id 7224218074CAA for ; Mon, 8 Jun 2020 11:44:49 +0000 (UTC) X-HE-Tag: key41_5208a2d26db9 X-Filterd-Recvd-Size: 7192 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf04.hostedemail.com (Postfix) with ESMTP for ; Mon, 8 Jun 2020 11:44:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=YbqL++npJfap+5388+JXfM2WdN9BHh6FymZsh2Jqhyc=; b=qnfCPEAoWWZ2xpmXOWVOxTu5iU abaTnBEt/WBI4e9vkP5iKToaUi/TWY5KSVFA9qmZOHSY2TemR0qtQCwxF9Y9dB27TZelMYArvfGs8 GvtYrQ6LARSMOxOpI2zuQ/n6v7okV+1fcIrSFgovLYSRUtk34pvAyMCbhaFMlkzWAXbZzw09gvE+X 0xIPv/A7RumdBQVycwdkjJTYk1/kFsXz2NXnWfu60qwxMA3vJcw1EM0r6y1PYrPUIH9sWXLWb2iJO N3kkpp3SFO1w7imh5JOQLoif814FA8vn2J5zkXQmN6pqHaNGhdiFgGCJtU1tGfesgwZ24wlJM+N9I ytqS1w9Q==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jiGCr-0006B5-Ug; Mon, 08 Jun 2020 11:44:45 +0000 Date: Mon, 8 Jun 2020 04:44:45 -0700 From: Matthew Wilcox To: Vlastimil Babka Cc: Chris Murphy , Linux Memory Management List , Chris Wilson , Hugh Dickins Subject: Re: 5.7.0 page allocation failure: order:0, mode:0x400d0 Message-ID: <20200608114445.GT19604@bombadil.infradead.org> References: <20200606151254.GO19604@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 7224218074CAA X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 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 Mon, Jun 08, 2020 at 11:08:33AM +0200, Vlastimil Babka wrote: > On 6/6/20 5:12 PM, Matthew Wilcox wrote: > > On Sat, Jun 06, 2020 at 01:38:57AM -0600, Chris Murphy wrote: > >> [ 5225.501756] gnome-shell: page allocation failure: order:0, > >> mode:0x400d0(__GFP_IO|__GFP_FS|__GFP_COMP|__GFP_RECLAIMABLE), > >> nodemask=(null),cpuset=/,mems_allowed=0 > > > > These are relatively liberal constraints on what the page allocator is > > allowed to do in order to succeed. > > They are not, it's not allowed to reclaim at all - __GFP_RECLAIMABLE is not the > same thing as __GFP_RECLAIM :) Ohh, __GFP_RECLAIMABLE is set because it's an XArray allocation and the slab can shrink the xarray nodes (by pruning page cache shadow entries), but __GFP_RECLAIM isn't set because shmem_gfp_pages() removes it. So slab is saying "you can reclaim", but shmem is saying "not in this context". > AFAICS the masks starts in shmem_gfp_pages() Ah! You mean in i915's shmem_get_pages(). > * Fail silently without starting the shrinker > noreclaim = mapping_gfp_constraint(mapping, ~__GFP_RECLAIM); > noreclaim |= __GFP_NORETRY | __GFP_NOWARN; > > possibly mapping has GFP_KERNEL, but this removes the GFP_RECLAIM part and adds > __GFP_NORETRY | __GFP_NOWARN > > if this fails (silently) there's a fallback > > But when this reaches __read_swap_cache_async() it does: > > /* May fail (-ENOMEM) if XArray node allocation failed. */ > err = add_to_swap_cache(new_page, entry, gfp_mask & GFP_KERNEL); > > So we lose the __GFP_NORETRY and importantly __GFP_NOWARN. Looks like you added > that with commit 8d93b41c09d1b :) I just moved code around: - /* - * call radix_tree_preload() while we can wait. - */ - err = radix_tree_maybe_preload(gfp_mask & GFP_KERNEL); - if (err) - break; so this problem could have occurred without this patch. Yes, it seems to me that the problem is that i915 set GFP_NOWARN and swap_state removed it. It's been this way since 2008 when Hugh committed f000944d03a5 I wouldn't have a problem with turning that '& GFP_KERNEL' into '& GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY'. i915 has been using __GFP_NOWARN | __GFP_NORETRY in this path since 2012 (!) with commit 6c085a728cf0 from Chris Wilson. So I guess we just got away with it until now? Adding Chris & Hugh. > ... > > >> [ 5225.502339] Mem-Info: > >> [ 5225.502345] active_anon:1433763 inactive_anon:207289 isolated_anon:182 > >> active_file:10333 inactive_file:8393 isolated_file:2 > >> unevictable:4657 dirty:100 writeback:0 unstable:0 > >> slab_reclaimable:16672 slab_unreclaimable:38093 > >> mapped:8919 shmem:4496 pagetables:10454 bounce:0 > >> free:26161 free_pcp:2054 free_cma:0 > >> [ 5225.502350] Node 0 active_anon:5735052kB inactive_anon:829156kB > >> active_file:41332kB inactive_file:33572kB unevictable:18628kB > >> isolated(anon):728kB isolated(file):8kB mapped:35676kB dirty:400kB > >> writeback:0kB shmem:17984kB shmem_thp: 0kB shmem_pmdmapped: 0kB > >> anon_thp: 0kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no > >> [ 5225.502352] Node 0 DMA free:15344kB min:128kB low:160kB high:192kB > >> reserved_highatomic:0KB active_anon:0kB inactive_anon:0kB > >> active_file:0kB inactive_file:0kB unevictable:0kB writepending:0kB > >> present:15988kB managed:15360kB mlocked:0kB kernel_stack:0kB > >> pagetables:0kB bounce:0kB free_pcp:0kB local_pcp:0kB free_cma:0kB > >> [ 5225.502357] lowmem_reserve[]: 0 2069 7810 7810 7810 > >> [ 5225.502360] Node 0 DMA32 free:40212kB min:17868kB low:22332kB > >> high:26796kB reserved_highatomic:0KB active_anon:1640016kB > >> inactive_anon:265148kB active_file:9856kB inactive_file:12584kB > >> unevictable:2968kB writepending:136kB present:2255864kB > >> managed:2157904kB mlocked:0kB kernel_stack:48kB pagetables:8524kB > >> bounce:0kB free_pcp:2904kB local_pcp:156kB free_cma:0kB > >> [ 5225.502365] lowmem_reserve[]: 0 0 5741 5741 5741 > >> [ 5225.502368] Node 0 Normal free:49088kB min:49584kB low:61980kB > >> high:74376kB reserved_highatomic:2048KB active_anon:4098076kB > >> inactive_anon:563004kB active_file:32212kB inactive_file:21312kB > >> unevictable:13680kB writepending:0kB present:6027264kB > >> managed:5879476kB mlocked:1792kB kernel_stack:7312kB > >> pagetables:33292kB bounce:0kB free_pcp:5388kB local_pcp:780kB > >> free_cma:0kB > >> [ 5225.502373] lowmem_reserve[]: 0 0 0 0 0 > >> [ 5225.502376] Node 0 DMA: 0*4kB 0*8kB 1*16kB (U) 1*32kB (U) 1*64kB > >> (U) 1*128kB (U) 1*256kB (U) 1*512kB (U) 0*1024kB 1*2048kB (M) 3*4096kB > >> (M) = 15344kB > >> [ 5225.502385] Node 0 DMA32: 1160*4kB (UM) 471*8kB (UME) 84*16kB (UM) > >> 103*32kB (UME) 116*64kB (UME) 59*128kB (UME) 26*256kB (UE) 8*512kB (E) > >> 2*1024kB (E) 0*2048kB 0*4096kB = 40824kB > >> [ 5225.502394] Node 0 Normal: 4778*4kB (UMH) 1400*8kB (UMEH) 346*16kB > >> (UMH) 270*32kB (UMEH) 20*64kB (UMEH) 20*128kB (MEH) 4*256kB (MEH) > >> 0*512kB 0*1024kB 0*2048kB 0*4096kB = 49352kB > > > > Umm ... seems like there's lots of memory free. Why did this fail? > > Normal is below min watermark, and for DMA32 and DMA the lowmem reserve most > likely kicked in. > >