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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 6A0B6C3F2CD for ; Mon, 23 Mar 2020 15:30:52 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3351F20409 for ; Mon, 23 Mar 2020 15:30:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3351F20409 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BEC856B0007; Mon, 23 Mar 2020 11:30:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B75256B0008; Mon, 23 Mar 2020 11:30:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AB2C46B000A; Mon, 23 Mar 2020 11:30:51 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0117.hostedemail.com [216.40.44.117]) by kanga.kvack.org (Postfix) with ESMTP id 90D186B0007 for ; Mon, 23 Mar 2020 11:30:51 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 589C28248047 for ; Mon, 23 Mar 2020 15:30:51 +0000 (UTC) X-FDA: 76627014702.09.crook61_419f6c8ae1135 X-HE-Tag: crook61_419f6c8ae1135 X-Filterd-Recvd-Size: 2266 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf37.hostedemail.com (Postfix) with ESMTP for ; Mon, 23 Mar 2020 15:30:50 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A9FD51FB; Mon, 23 Mar 2020 08:30:48 -0700 (PDT) Received: from e107158-lin.cambridge.arm.com (e107158-lin.cambridge.arm.com [10.1.195.21]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 206F43F7C3; Mon, 23 Mar 2020 08:30:48 -0700 (PDT) Date: Mon, 23 Mar 2020 15:30:45 +0000 From: Qais Yousef To: Andrew Morton , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org Subject: Re: lockdep warning in sys_swapon Message-ID: <20200323153045.s7ag3lrvfe2cpiiw@e107158-lin.cambridge.arm.com> References: <20200323151725.gayvs5g6h5adwqkd@e107158-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200323151725.gayvs5g6h5adwqkd@e107158-lin.cambridge.arm.com> User-Agent: NeoMutt/20171215 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000740, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 03/23/20 15:17, Qais Yousef wrote: > Hi > > I hit the following 2 warnings when running with LOCKDEP=y on arm64 platform > (juno-r2), running on v5.6-rc6 > > The 1st one is when I execute `swapon -a`. The 2nd one happens at boot. I have > /dev/sda2 as my swap in /etc/fstab > > Note that I either hit 1 OR 2, but didn't hit both warnings at the same time, > yet at least. > > /dev/sda2 is a usb flash drive, in case it matters somehow. By the way, I noticed that in claim_swapfile() if we fail we don't release the lock. Shouldn't we release the lock here? I tried with that FWIW, but it had no effect on the warnings. diff --git a/mm/swapfile.c b/mm/swapfile.c index b2a2e45c9a36..0293e8c7b472 100644 --- a/mm/swapfile.c +++ b/mm/swapfile.c @@ -2900,8 +2900,10 @@ static int claim_swapfile(struct swap_info_struct *p, struct inode *inode) } inode_lock(inode); - if (IS_SWAPFILE(inode)) + if (IS_SWAPFILE(inode)) { + inode_unlock(inode); return -EBUSY; + } return 0; } Thanks -- Qais Yousef