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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 C9E84C07E9D for ; Mon, 19 Jul 2021 12:24:01 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5F22D6113B for ; Mon, 19 Jul 2021 12:24:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5F22D6113B Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=natalenko.name Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E55FA8D00F4; Mon, 19 Jul 2021 08:24:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E07008D00EC; Mon, 19 Jul 2021 08:24:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CA7B68D00F4; Mon, 19 Jul 2021 08:24:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0188.hostedemail.com [216.40.44.188]) by kanga.kvack.org (Postfix) with ESMTP id 92C738D00EC for ; Mon, 19 Jul 2021 08:24:01 -0400 (EDT) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 28B28180480AB for ; Mon, 19 Jul 2021 12:24:00 +0000 (UTC) X-FDA: 78379254240.15.D57DEEF Received: from vulcan.natalenko.name (vulcan.natalenko.name [104.207.131.136]) by imf09.hostedemail.com (Postfix) with ESMTP id 7EBA13000103 for ; Mon, 19 Jul 2021 12:23:59 +0000 (UTC) Received: from spock.localnet (unknown [151.237.229.131]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by vulcan.natalenko.name (Postfix) with ESMTPSA id E3F9CB3F5CE; Mon, 19 Jul 2021 14:23:56 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=natalenko.name; s=dkim-20170712; t=1626697437; 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=K5psd6Gyst7jbmkEY35fCzySbAqC76tMvxDPI72IBLU=; b=cQTeim98LKn7CJbBdHfrCSWS7Gz5gbDejjwVrzQDQtHVIIhUvNWfN/pUwkdLmFNc0qLRSq XNvt1ZgCZ9ZRF3Abv0BoYfh0kaLDqY4ylhReu8cF9PxgYOfJwGQ0JQbelnzYns9x1wJUp2 SRhuOZDLzgWOuQUS6G0xqoXx+t4oJ/8= From: Oleksandr Natalenko To: Matthew Wilcox Cc: Miaohe Lin , Boqun Feng , Zhouyi Zhou , paulmck@kernel.org, linux-kernel , stable@vger.kernel.org, Chris Clayton , Chris Rankin , Josh Triplett , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Joel Fernandes , rcu , Andrew Morton , Linux-MM , "Huang, Ying" , gregkh@linuxfoundation.org Subject: Re: linux-5.13.2: warning from kernel/rcu/tree_plugin.h:359 Date: Mon, 19 Jul 2021 14:23:55 +0200 Message-ID: <2237123.PRLUojbHBq@natalenko.name> In-Reply-To: References: <5812280.fcLxn8YiTP@natalenko.name> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="UTF-8" Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=natalenko.name header.s=dkim-20170712 header.b=cQTeim98; spf=pass (imf09.hostedemail.com: domain of oleksandr@natalenko.name designates 104.207.131.136 as permitted sender) smtp.mailfrom=oleksandr@natalenko.name; dmarc=pass (policy=reject) header.from=natalenko.name X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 7EBA13000103 X-Stat-Signature: zrjnxqhjy8xd99d681fip1i1e9cqomcm X-HE-Tag: 1626697439-950621 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 pond=C4=9Bl=C3=AD 19. =C4=8Dervence 2021 14:16:04 CEST Matthew Wilcox wr= ote: > On Mon, Jul 19, 2021 at 02:12:15PM +0200, Oleksandr Natalenko wrote: > > On pond=C4=9Bl=C3=AD 19. =C4=8Dervence 2021 14:08:37 CEST Miaohe Lin wr= ote: > > > On 2021/7/19 19:59, Oleksandr Natalenko wrote: > > > > On pond=C4=9Bl=C3=AD 19. =C4=8Dervence 2021 13:50:07 CEST Miaohe Li= n wrote: > > > >> On 2021/7/19 19:22, Matthew Wilcox wrote: > > > >>> On Mon, Jul 19, 2021 at 07:12:58PM +0800, Miaohe Lin wrote: > > > >>>> When in the commit 2799e77529c2a, we're using the percpu_ref to > > > >>>> serialize > > > >>>> against concurrent swapoff, i.e. there's percpu_ref inside > > > >>>> get_swap_device() instead of rcu_read_lock(). Please see commit > > > >>>> 63d8620ecf93 ("mm/swapfile: use percpu_ref to serialize against > > > >>>> concurrent swapoff") for detail. > > > >>>=20 > > > >>> Oh, so this is a backport problem. 2799e77529c2 was backported > > > >>> without > > > >>> its prerequisite 63d8620ecf93. Greg, probably best to just drop > > > >>=20 > > > >> Yes, they're posted as a patch set: > > > >>=20 > > > >> https://lkml.kernel.org/r/20210426123316.806267-1-linmiaohe@huawei= =2Eco > > > >> m > > > >>=20 > > > >>> 2799e77529c2 from all stable trees; the race described is not very > > > >>> important (swapoff vs reading a page back from that swap device). > > > >>> . > > > >>=20 > > > >> The swapoff races with reading a page back from that swap device > > > >> should > > > >> be > > > >> really uncommon as most users only do swapoff when the system is > > > >> going to > > > >> shutdown. > > > >>=20 > > > >> Sorry for the trouble! > > > >=20 > > > > git log --oneline v5.13..v5.13.3 --author=3D"Miaohe Lin" > > > > 11ebc09e50dc mm/zswap.c: fix two bugs in zswap_writeback_entry() > > > > 95d192da198d mm/z3fold: use release_z3fold_page_locked() to release > > > > locked > > > > z3fold page > > > > ccb7848e2344 mm/z3fold: fix potential memory leak in > > > > z3fold_destroy_pool() > > > > 9f7229c901c1 mm/huge_memory.c: don't discard hugepage if other > > > > processes > > > > are mapping it > > > > f13259175e4f mm/huge_memory.c: add missing read-only THP checking in > > > > transparent_hugepage_enabled() > > > > afafd371e7de mm/huge_memory.c: remove dedicated macro > > > > HPAGE_CACHE_INDEX_MASK a533a21b692f mm/shmem: fix shmem_swapin() ra= ce > > > > with swapoff > > > > c3b39134bbd0 swap: fix do_swap_page() race with swapoff > > > >=20 > > > > Do you suggest reverting "mm/shmem: fix shmem_swapin() race with > > > > swapoff" > > > > as well? > > >=20 > > > This patch also rely on its prerequisite 63d8620ecf93. I think we sho= uld > > > either revert any commit in this series or just backport the entire > > > series. > >=20 > > Then why not just pick up 2 more patches instead of dropping 2 patches. > > Greg, could you please make sure the whole series from [1] gets pulled? >=20 > Because none of these patches should have been backported in the first > place. It's just not worth the destabilisation. What about the rest then? git log --oneline v5.13..v5.13.3 -- mm/ | wc -l 18 Those look to be fixes, these ones too. =2D-=20 Oleksandr Natalenko (post-factum)