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=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 C2DD1CA9EC0 for ; Mon, 28 Oct 2019 15:27:29 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 7648221783 for ; Mon, 28 Oct 2019 15:27:29 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="DQnpWjaq" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7648221783 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 25F6D6B029D; Mon, 28 Oct 2019 11:27:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 210046B029E; Mon, 28 Oct 2019 11:27:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 127206B029F; Mon, 28 Oct 2019 11:27:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0108.hostedemail.com [216.40.44.108]) by kanga.kvack.org (Postfix) with ESMTP id E238C6B029D for ; Mon, 28 Oct 2019 11:27:28 -0400 (EDT) Received: from smtpin24.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 7BF9A181AEF32 for ; Mon, 28 Oct 2019 15:27:28 +0000 (UTC) X-FDA: 76093572576.24.pin11_412a17a00302c X-HE-Tag: pin11_412a17a00302c X-Filterd-Recvd-Size: 6438 Received: from us-smtp-delivery-1.mimecast.com (us-smtp-1.mimecast.com [207.211.31.81]) by imf34.hostedemail.com (Postfix) with ESMTP for ; Mon, 28 Oct 2019 15:27:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1572276447; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=XkydJCbBHnNFMqtcPOS9x9UJENHlU5nvvm8ihnTgRFE=; b=DQnpWjaqptONsOekv1jdTfNE6cM+HJhg0uf3syY3iqj3NYuEQvSlqPfJd7t9JNPbYcAwRe i+CltsCOhaEeBficWo9lUrbuhESxMOUa5jN0T1zODWpsJdi9nTXFtUtFOGha5xq9myaUQ7 ub2gefd9SxzZQFw3Ja4w9rKj3M1R+mU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-347-MMTObWBiM0W1UFyliULyCQ-1; Mon, 28 Oct 2019 11:27:22 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 314DD801E5C; Mon, 28 Oct 2019 15:27:20 +0000 (UTC) Received: from [10.36.117.63] (ovpn-117-63.ams2.redhat.com [10.36.117.63]) by smtp.corp.redhat.com (Postfix) with ESMTP id F0BDA60850; Mon, 28 Oct 2019 15:27:17 +0000 (UTC) Subject: Re: [PATCH] mm: fix unevictable page reclaim when calling madvise_pageout To: zhong jiang , akpm@linux-foundation.org Cc: mhocko@suse.com, hannes@cmpxchg.org, ktkhai@virtuozzo.com, linux-mm@kvack.org References: <1572275317-63910-1-git-send-email-zhongjiang@huawei.com> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <3ac2e87d-2899-ab17-8b0b-8aa6a5035d4a@redhat.com> Date: Mon, 28 Oct 2019 16:27:17 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <1572275317-63910-1-git-send-email-zhongjiang@huawei.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-MC-Unique: MMTObWBiM0W1UFyliULyCQ-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable 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 28.10.19 16:08, zhong jiang wrote: > Recently, I hit the following issue when running in the upstream. >=20 > kernel BUG at mm/vmscan.c:1521! > invalid opcode: 0000 [#1] SMP KASAN PTI > CPU: 0 PID: 23385 Comm: syz-executor.6 Not tainted 5.4.0-rc4+ #1 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubunt= u1 04/01/2014 > RIP: 0010:shrink_page_list+0x12b6/0x3530 mm/vmscan.c:1521 > Code: de f5 ff ff e8 ab 79 eb ff 4c 89 f7 e8 43 33 0d 00 e9 cc f5 ff ff e= 8 99 79 eb ff 48 c7 c6 a0 34 2b a0 4c 89 f7 e8 1a 4d 05 00 <0f> 0b e8 83 79= eb ff 48 89 d8 48 c1 e8 03 42 80 3c 38 00 0f 85 74 > RSP: 0018:ffff88819a3df5a0 EFLAGS: 00010286 > RAX: 0000000000040000 RBX: ffffea00061c3980 RCX: ffffffff814fba36 > RDX: 00000000000056f7 RSI: ffffc9000c02c000 RDI: ffff8881f70268cc > RBP: ffff88819a3df898 R08: ffffed103ee05de0 R09: ffffed103ee05de0 > R10: 0000000000000001 R11: ffffed103ee05ddf R12: ffff88819a3df6f0 > R13: ffff88819a3df6f0 R14: ffffea00061c3980 R15: dffffc0000000000 > FS: 00007f21b9d8e700(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000= 000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000001b2d621000 CR3: 00000001c8c46004 CR4: 00000000007606f0 > DR0: 0000000020000140 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 > PKRU: 55555554 > Call Trace: > reclaim_pages+0x499/0x800 mm/vmscan.c:2188 > madvise_cold_or_pageout_pte_range+0x58a/0x710 mm/madvise.c:453 > walk_pmd_range mm/pagewalk.c:53 [inline] > walk_pud_range mm/pagewalk.c:112 [inline] > walk_p4d_range mm/pagewalk.c:139 [inline] > walk_pgd_range mm/pagewalk.c:166 [inline] > __walk_page_range+0x45a/0xc20 mm/pagewalk.c:261 > walk_page_range+0x179/0x310 mm/pagewalk.c:349 > madvise_pageout_page_range mm/madvise.c:506 [inline] > madvise_pageout+0x1f0/0x330 mm/madvise.c:542 > madvise_vma mm/madvise.c:931 [inline] > __do_sys_madvise+0x7d2/0x1600 mm/madvise.c:1113 > do_syscall_64+0x9f/0x4c0 arch/x86/entry/common.c:290 > entry_SYSCALL_64_after_hwframe+0x49/0xbe >=20 > madvise_pageout access the specified range of the vma and isolate > them, then run shrink_page_list to reclaim the memory. But It also > isolate the unevictable page to reclaim. Hence, we can catch the > cases in shrink_page_list. >=20 > We can fix it by preventing unevictable page from isolating. > Another way to fix the issue by removing the condition of > BUG_ON(PageUnevictable(page)) in shrink_page_list. I think it > is better to use the latter. Because We has taken the unevictable > page and skip it into account in shrink_page_list. I really don't understand the last sentence. Looks like something got messed up :) >=20 > Signed-off-by: zhong jiang > --- > mm/vmscan.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) >=20 > diff --git a/mm/vmscan.c b/mm/vmscan.c > index f7d1301..1c6e959 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -1524,7 +1524,7 @@ static unsigned long shrink_page_list(struct list_h= ead *page_list, > =09=09unlock_page(page); > keep: > =09=09list_add(&page->lru, &ret_pages); > -=09=09VM_BUG_ON_PAGE(PageLRU(page) || PageUnevictable(page), page); > +=09=09VM_BUG_ON_PAGE(PageLRU(page), page); So, this comes from commit b291f000393f5a0b679012b39d79fbc85c018233 Author: Nick Piggin Date: Sat Oct 18 20:26:44 2008 -0700 mlock: mlocked pages are unevictable =20 Make sure that mlocked pages also live on the unevictable LRU, so kswap= d will not scan them over and over again. That patch is fairly old. How come we can suddenly trigger this? Which commit is responsible for that? Was it always broken? I can see that commit ad6b67041a45497261617d7a28b15159b202cb5a Author: Minchan Kim Date: Wed May 3 14:54:13 2017 -0700 mm: remove SWAP_MLOCK in ttu Performed some changes in that area. But also some time ago. --=20 Thanks, David / dhildenb