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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 ADBBAC433E0 for ; Wed, 10 Jun 2020 01:21:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7A29720691 for ; Wed, 10 Jun 2020 01:21:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591752078; bh=QJTWoYPEt98yHwKpVAXT3b+1WBVQu7Qq4xcRaxMAhH8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=tU7sTy/65D+EaXUs9cqFbA6YgFJTnye1JMQe1hM33hYWF77UJThDMRPit+lVpuHds +5tH7Hn2XT8AgoW9Qzdp/2kh/J2GiSwZ8rc5Jh3V9F8K/aSSHSfI37wQsQFQBAtYqr RJ+QgsofzDKRzSdWPJ28LPOR4po+qBsElcpOfCl4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726156AbgFJBVR (ORCPT ); Tue, 9 Jun 2020 21:21:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54814 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726040AbgFJBVQ (ORCPT ); Tue, 9 Jun 2020 21:21:16 -0400 Received: from mail-pl1-x643.google.com (mail-pl1-x643.google.com [IPv6:2607:f8b0:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 193ADC05BD1E for ; Tue, 9 Jun 2020 18:21:16 -0700 (PDT) Received: by mail-pl1-x643.google.com with SMTP id g12so285166pll.10 for ; Tue, 09 Jun 2020 18:21:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=DcwQVuLC758yK0I+tGrD+0w5Fr7cPaDEkr2hA8CA5cw=; b=GembKLP+4i8De+vcRFzj61gw6w2TQI1whOJMmAyRe7jjHjatkw762cncoNGx1a60Iw 39gOTRMD9wvGd0IQlfumotxVlt65D7/rYIoEUSB1lxucfJWlo/+NrDI0WJhaNgmr2VdX 6ak+YtPzLGIzkpxpd0fnxSWcejGRLr+WufVvQO2X1d7dEqecMLUyXSb7IzxrcPh+c7DQ yod0z4J4WtAI/773cH8uBXkOj+3UJ035zSE2BUHYI+P6kKK4tP8o91ysa8CC1qwXU38W G6bF5sqqLZgHTrtLF9yK2DiU/68zF85AWQ1BL8YKhW/4uUUmcmyEHp77S4DeSP3KmTU1 qh4Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to; bh=DcwQVuLC758yK0I+tGrD+0w5Fr7cPaDEkr2hA8CA5cw=; b=m5EjP0hPBlI+qrox9AJjZ4qGDtxM0aJwtRiXktrbwk+rvKItGddSMp0VPJPEqb8FIT 3zMqKydvrHZacqx5upy/dLheszSSU2zIMVmxyyzD9igoM2HsjEasELhO1VY1T44084U6 xiRp5d/ZcQilyR9JovOmjSgp8F7bbp9jz1wstAXLDDKj1PxIaPDwjCRQWMBhio8wGbnc AUzu2+B3u5a+rpK+dJZ88s0dJ4TLc1dWtQYlnIF+TJLfacSjb8HoB+zfXkfm3WP472pl 0A/eYw5cPjPxOkjuJfHXQD+gGgSOmusKtmK3e1AfA9C3Dp+Q/d1lHrb9FUELYuZUEe9k 6E9g== X-Gm-Message-State: AOAM530MJLdema9PGnGaXAbZ5GoYQU0LbvDkZbLE3UKXu9NAgsy9dQwd SraoNmGLor+WLYDlAsJ9JyA= X-Google-Smtp-Source: ABdhPJxONRRsAqs+xQ6lqEjhQAHN/WNWzzfrCv9Zd8aIN8N20pC3btdb37Bsd9inXQ2wecJtg5D7UQ== X-Received: by 2002:a17:902:c082:: with SMTP id j2mr95551pld.175.1591752075371; Tue, 09 Jun 2020 18:21:15 -0700 (PDT) Received: from google.com ([2601:647:4001:3000::e690]) by smtp.gmail.com with ESMTPSA id l23sm9323129pgc.55.2020.06.09.18.21.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 Jun 2020 18:21:14 -0700 (PDT) Date: Tue, 9 Jun 2020 18:21:12 -0700 From: Minchan Kim To: Jaewon Kim Cc: mgorman@techsingularity.net, mgorman@suse.de, hannes@cmpxchg.org, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, jaewon31.kim@gmail.com, ytk.lee@samsung.com, cmlaika.kim@samsung.com Subject: Re: [PATCH] page_alloc: consider highatomic reserve in wmartermark fast Message-ID: <20200610012112.GA239587@google.com> References: <20200609095128.8112-1-jaewon31.kim@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200609095128.8112-1-jaewon31.kim@samsung.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jaewon, On Tue, Jun 09, 2020 at 06:51:28PM +0900, Jaewon Kim wrote: > zone_watermark_fast was introduced by commit 48ee5f3696f6 ("mm, > page_alloc: shortcut watermark checks for order-0 pages"). The commit > simply checks if free pages is bigger than watermark without additional > calculation such like reducing watermark. > > It considered free cma pages but it did not consider highatomic > reserved. This may incur exhaustion of free pages except high order > atomic free pages. > > Assume that reserved_highatomic pageblock is bigger than watermark min, > and there are only few free pages except high order atomic free. Because > zone_watermark_fast passes the allocation without considering high order > atomic free, normal reclaimable allocation like GFP_HIGHUSER will > consume all the free pages. Then finally order-0 atomic allocation may > fail on allocation. > > This means watermark min is not protected against non-atomic allocation. > The order-0 atomic allocation with ALLOC_HARDER unwantedly can be > failed. Additionally the __GFP_MEMALLOC allocation with > ALLOC_NO_WATERMARKS also can be failed. > > To avoid the problem, zone_watermark_fast should consider highatomic > reserve. If the actual size of high atomic free is counted accurately > like cma free, we may use it. On this patch just use > nr_reserved_highatomic. > > This is trace log which shows GFP_HIGHUSER consumes free pages right > before ALLOC_NO_WATERMARKS. > > <...>-22275 [006] .... 889.213383: mm_page_alloc: page=00000000d2be5665 pfn=970744 order=0 migratetype=0 nr_free=3650 gfp_flags=GFP_HIGHUSER|__GFP_ZERO > <...>-22275 [006] .... 889.213385: mm_page_alloc: page=000000004b2335c2 pfn=970745 order=0 migratetype=0 nr_free=3650 gfp_flags=GFP_HIGHUSER|__GFP_ZERO > <...>-22275 [006] .... 889.213387: mm_page_alloc: page=00000000017272e1 pfn=970278 order=0 migratetype=0 nr_free=3650 gfp_flags=GFP_HIGHUSER|__GFP_ZERO > <...>-22275 [006] .... 889.213389: mm_page_alloc: page=00000000c4be79fb pfn=970279 order=0 migratetype=0 nr_free=3650 gfp_flags=GFP_HIGHUSER|__GFP_ZERO > <...>-22275 [006] .... 889.213391: mm_page_alloc: page=00000000f8a51d4f pfn=970260 order=0 migratetype=0 nr_free=3650 gfp_flags=GFP_HIGHUSER|__GFP_ZERO > <...>-22275 [006] .... 889.213393: mm_page_alloc: page=000000006ba8f5ac pfn=970261 order=0 migratetype=0 nr_free=3650 gfp_flags=GFP_HIGHUSER|__GFP_ZERO > <...>-22275 [006] .... 889.213395: mm_page_alloc: page=00000000819f1cd3 pfn=970196 order=0 migratetype=0 nr_free=3650 gfp_flags=GFP_HIGHUSER|__GFP_ZERO > <...>-22275 [006] .... 889.213396: mm_page_alloc: page=00000000f6b72a64 pfn=970197 order=0 migratetype=0 nr_free=3650 gfp_flags=GFP_HIGHUSER|__GFP_ZERO > kswapd0-1207 [005] ...1 889.213398: mm_page_alloc: page= (null) pfn=0 order=0 migratetype=1 nr_free=3650 gfp_flags=GFP_NOWAIT|__GFP_HIGHMEM|__GFP_NOWARN|__GFP_MOVABLE > > This is an example of ALLOC_HARDER allocation failure. > > <4>[ 6207.637280] [3: Binder:9343_3:22875] Binder:9343_3: page allocation failure: order:0, mode:0x480020(GFP_ATOMIC), nodemask=(null) > <4>[ 6207.637311] [3: Binder:9343_3:22875] Call trace: > <4>[ 6207.637346] [3: Binder:9343_3:22875] [] dump_stack+0xb8/0xf0 > <4>[ 6207.637356] [3: Binder:9343_3:22875] [] warn_alloc+0xd8/0x12c > <4>[ 6207.637365] [3: Binder:9343_3:22875] [] __alloc_pages_nodemask+0x120c/0x1250 > <4>[ 6207.637374] [3: Binder:9343_3:22875] [] new_slab+0x128/0x604 > <4>[ 6207.637381] [3: Binder:9343_3:22875] [] ___slab_alloc+0x508/0x670 > <4>[ 6207.637387] [3: Binder:9343_3:22875] [] __kmalloc+0x2f8/0x310 > <4>[ 6207.637396] [3: Binder:9343_3:22875] [] context_struct_to_string+0x104/0x1cc > <4>[ 6207.637404] [3: Binder:9343_3:22875] [] security_sid_to_context_core+0x74/0x144 > <4>[ 6207.637412] [3: Binder:9343_3:22875] [] security_sid_to_context+0x10/0x18 > <4>[ 6207.637421] [3: Binder:9343_3:22875] [] selinux_secid_to_secctx+0x20/0x28 > <4>[ 6207.637430] [3: Binder:9343_3:22875] [] security_secid_to_secctx+0x3c/0x70 > <4>[ 6207.637442] [3: Binder:9343_3:22875] [] binder_transaction+0xe68/0x454c > <4>[ 6207.637569] [3: Binder:9343_3:22875] Mem-Info: > <4>[ 6207.637595] [3: Binder:9343_3:22875] active_anon:102061 inactive_anon:81551 isolated_anon:0 > <4>[ 6207.637595] [3: Binder:9343_3:22875] active_file:59102 inactive_file:68924 isolated_file:64 > <4>[ 6207.637595] [3: Binder:9343_3:22875] unevictable:611 dirty:63 writeback:0 unstable:0 > <4>[ 6207.637595] [3: Binder:9343_3:22875] slab_reclaimable:13324 slab_unreclaimable:44354 > <4>[ 6207.637595] [3: Binder:9343_3:22875] mapped:83015 shmem:4858 pagetables:26316 bounce:0 > <4>[ 6207.637595] [3: Binder:9343_3:22875] free:2727 free_pcp:1035 free_cma:178 > <4>[ 6207.637616] [3: Binder:9343_3:22875] Node 0 active_anon:408244kB inactive_anon:326204kB active_file:236408kB inactive_file:275696kB unevictable:2444kB isolated(anon):0kB isolated(file):256kB mapped:332060kB dirty:252kB writeback:0kB shmem:19432kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no > <4>[ 6207.637627] [3: Binder:9343_3:22875] Normal free:10908kB min:6192kB low:44388kB high:47060kB active_anon:409160kB inactive_anon:325924kB active_file:235820kB inactive_file:276628kB unevictable:2444kB writepending:252kB present:3076096kB managed:2673676kB mlocked:2444kB kernel_stack:62512kB pagetables:105264kB bounce:0kB free_pcp:4140kB local_pcp:40kB free_cma:712kB > <4>[ 6207.637632] [3: Binder:9343_3:22875] lowmem_reserve[]: 0 0 > <4>[ 6207.637637] [3: Binder:9343_3:22875] Normal: 505*4kB (H) 357*8kB (H) 201*16kB (H) 65*32kB (H) 1*64kB (H) 0*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB 0*4096kB = 10236kB > <4>[ 6207.637655] [3: Binder:9343_3:22875] 138826 total pagecache pages > <4>[ 6207.637663] [3: Binder:9343_3:22875] 5460 pages in swap cache > <4>[ 6207.637668] [3: Binder:9343_3:22875] Swap cache stats: add 8273090, delete 8267506, find 1004381/4060142 > > This is an example of ALLOC_NO_WATERMARKS allocation failure. > > <6>[ 156.701551] [4: kswapd0: 1209] kswapd0 cpuset=/ mems_allowed=0 > <4>[ 156.701563] [4: kswapd0: 1209] CPU: 4 PID: 1209 Comm: kswapd0 Tainted: G W 4.14.113-18113966 #1 > <4>[ 156.701572] [4: kswapd0: 1209] Call trace: > <4>[ 156.701605] [4: kswapd0: 1209] [<0000000000000000>] dump_stack+0x68/0x90 > <4>[ 156.701612] [4: kswapd0: 1209] [<0000000000000000>] warn_alloc+0x104/0x198 > <4>[ 156.701617] [4: kswapd0: 1209] [<0000000000000000>] __alloc_pages_nodemask+0xdc0/0xdf0 > <4>[ 156.701623] [4: kswapd0: 1209] [<0000000000000000>] zs_malloc+0x148/0x3d0 > <4>[ 156.701630] [4: kswapd0: 1209] [<0000000000000000>] zram_bvec_rw+0x250/0x568 > <4>[ 156.701634] [4: kswapd0: 1209] [<0000000000000000>] zram_rw_page+0x8c/0xe0 > <4>[ 156.701640] [4: kswapd0: 1209] [<0000000000000000>] bdev_write_page+0x70/0xbc > <4>[ 156.701645] [4: kswapd0: 1209] [<0000000000000000>] __swap_writepage+0x58/0x37c > <4>[ 156.701649] [4: kswapd0: 1209] [<0000000000000000>] swap_writepage+0x40/0x4c > <4>[ 156.701654] [4: kswapd0: 1209] [<0000000000000000>] shrink_page_list+0xc3c/0xf54 > <4>[ 156.701659] [4: kswapd0: 1209] [<0000000000000000>] shrink_inactive_list+0x2b0/0x61c > <4>[ 156.701664] [4: kswapd0: 1209] [<0000000000000000>] shrink_node_memcg+0x23c/0x618 > <4>[ 156.701668] [4: kswapd0: 1209] [<0000000000000000>] shrink_node+0x1c8/0x304 > <4>[ 156.701673] [4: kswapd0: 1209] [<0000000000000000>] kswapd+0x680/0x7c4 > <4>[ 156.701679] [4: kswapd0: 1209] [<0000000000000000>] kthread+0x110/0x120 > <4>[ 156.701684] [4: kswapd0: 1209] [<0000000000000000>] ret_from_fork+0x10/0x18 > <4>[ 156.701689] [4: kswapd0: 1209] Mem-Info: > <4>[ 156.701712] [4: kswapd0: 1209] active_anon:88690 inactive_anon:88630 isolated_anon:0 > <4>[ 156.701712] [4: kswapd0: 1209] active_file:99173 inactive_file:169305 isolated_file:32 > <4>[ 156.701712] [4: kswapd0: 1209] unevictable:48292 dirty:538 writeback:38 unstable:0 > <4>[ 156.701712] [4: kswapd0: 1209] slab_reclaimable:15131 slab_unreclaimable:47762 > <4>[ 156.701712] [4: kswapd0: 1209] mapped:274654 shmem:2824 pagetables:25088 bounce:0 > <4>[ 156.701712] [4: kswapd0: 1209] free:2489 free_pcp:444 free_cma:3 > <4>[ 156.701728] [4: kswapd0: 1209] Node 0 active_anon:354760kB inactive_anon:354520kB active_file:396692kB inactive_file:677220kB unevictable:193168kB isolated(anon):0kB isolated(file):128kB mapped:1098616kB dirty:2152kB writeback:152kB shmem:11296kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no > <4>[ 156.701738] [4: kswapd0: 1209] Normal free:9956kB min:7428kB low:93440kB high:97032kB active_anon:355176kB inactive_anon:354580kB active_file:396196kB inactive_file:677284kB unevictable:193168kB writepending:2304kB present:4081664kB managed:3593324kB mlocked:193168kB kernel_stack:55008kB pagetables:100352kB bounce:0kB free_pcp:1776kB local_pcp:656kB free_cma:12kB > <4>[ 156.701741] [4: kswapd0: 1209] lowmem_reserve[]: 0 0 > <4>[ 156.701747] [4: kswapd0: 1209] Normal: 196*4kB (H) 141*8kB (H) 109*16kB (H) 63*32kB (H) 20*64kB (H) 8*128kB (H) 2*256kB (H) 1*512kB (H) 0*1024kB 0*2048kB 0*4096kB = 9000kB > > Signed-off-by: Jaewon Kim > Reported-by: Yong-Taek Lee > --- > mm/page_alloc.c | 13 +++++++++++-- > 1 file changed, 11 insertions(+), 2 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 13cc653122b7..00869378d387 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -3553,6 +3553,11 @@ static inline bool zone_watermark_fast(struct zone *z, unsigned int order, > { > long free_pages = zone_page_state(z, NR_FREE_PAGES); > long cma_pages = 0; > + long highatomic = 0; > + const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM)); > + > + if (likely(!alloc_harder)) > + highatomic = z->nr_reserved_highatomic; > > #ifdef CONFIG_CMA > /* If allocation can't use CMA areas don't use free CMA pages */ > @@ -3567,8 +3572,12 @@ static inline bool zone_watermark_fast(struct zone *z, unsigned int order, > * the caller is !atomic then it'll uselessly search the free > * list. That corner case is then slower but it is harmless. > */ > - if (!order && (free_pages - cma_pages) > mark + z->lowmem_reserve[classzone_idx]) > - return true; > + if (!order) { > + long fast_free = free_pages - cma_pages - highatomic; With your change, it seems we share most code for getting free_pages between zone_watermark_fast and __zone_watermark_ok. Only difference between them is min calculation. If so, can we share most code between them via introducing like __zone_watermark_free static inline function? So, we didn't miss one place in future if we change something. > + > + if (fast_free > mark + z->lowmem_reserve[classzone_idx]) > + return true; > + } > > return __zone_watermark_ok(z, order, mark, classzone_idx, alloc_flags, > free_pages); > -- > 2.17.1 >