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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB12FC433F5 for ; Thu, 3 Feb 2022 23:19:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355919AbiBCXTP (ORCPT ); Thu, 3 Feb 2022 18:19:15 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:43540 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233188AbiBCXTO (ORCPT ); Thu, 3 Feb 2022 18:19:14 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C87C561842; Thu, 3 Feb 2022 23:19:13 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4669C340E8; Thu, 3 Feb 2022 23:19:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1643930353; bh=QAHuBZ+lX2RUpSHwgEocw6rmoaPtXDKxXRloyq8ZEec=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=CjspKTS1bIPfibcKITrREBKeKQlZmkOykOg6E5BXy0zEwtnZIRsD4PFTz6byuzX9r +lFOI56eEYmixY6vm3Qq137KAT2W9/9MD417k/Q5JaOKMvDs+3P27ZGynHSXbyEx35 c/dnEzqXOQRUU29oM0utwLQvmRN+owV/pen03xtc= Date: Thu, 3 Feb 2022 15:19:12 -0800 From: Andrew Morton To: Roman Gushchin Cc: , , Alexander Egorenkov , Waiman Long , Tejun Heo , Johannes Weiner , Shakeel Butt , Jeremy Linton , Subject: Re: [PATCH RESEND] mm: memcg: synchronize objcg lists with a dedicated spinlock Message-Id: <20220203151912.87d47b82c1bc3f0d56be0e3a@linux-foundation.org> In-Reply-To: References: X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 1 Feb 2022 14:33:04 -0800 Roman Gushchin wrote: > Alexander reported a circular lock dependency revealed by the mmap1 > ltp test: > LOCKDEP_CIRCULAR (suite: ltp, case: mtest06 (mmap1)) > > ... > > Fixes: bf4f059954dc ("mm: memcg/slab: obj_cgroup API") I'm thinking it needs cc:stable. It sounds unlikely that we'll hit it in real life, but lockdep splats are concerning and I expect downstream kernel consumers will end up merging this anyway, for this reason. From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: Re: [PATCH RESEND] mm: memcg: synchronize objcg lists with a dedicated spinlock Date: Thu, 3 Feb 2022 15:19:12 -0800 Message-ID: <20220203151912.87d47b82c1bc3f0d56be0e3a@linux-foundation.org> References: Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1643930353; bh=QAHuBZ+lX2RUpSHwgEocw6rmoaPtXDKxXRloyq8ZEec=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=CjspKTS1bIPfibcKITrREBKeKQlZmkOykOg6E5BXy0zEwtnZIRsD4PFTz6byuzX9r +lFOI56eEYmixY6vm3Qq137KAT2W9/9MD417k/Q5JaOKMvDs+3P27ZGynHSXbyEx35 c/dnEzqXOQRUU29oM0utwLQvmRN+owV/pen03xtc= In-Reply-To: List-ID: Content-Type: text/plain; charset="us-ascii" To: Roman Gushchin Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Alexander Egorenkov , Waiman Long , Tejun Heo , Johannes Weiner , Shakeel Butt , Jeremy Linton , cgroups@vger.kernel.org On Tue, 1 Feb 2022 14:33:04 -0800 Roman Gushchin wrote: > Alexander reported a circular lock dependency revealed by the mmap1 > ltp test: > LOCKDEP_CIRCULAR (suite: ltp, case: mtest06 (mmap1)) > > ... > > Fixes: bf4f059954dc ("mm: memcg/slab: obj_cgroup API") I'm thinking it needs cc:stable. It sounds unlikely that we'll hit it in real life, but lockdep splats are concerning and I expect downstream kernel consumers will end up merging this anyway, for this reason.