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 9B406C0015E for ; Thu, 6 Jul 2023 00:44:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232618AbjGFAop (ORCPT ); Wed, 5 Jul 2023 20:44:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34574 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231218AbjGFAoo (ORCPT ); Wed, 5 Jul 2023 20:44:44 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 87EAB19A9; Wed, 5 Jul 2023 17:44:43 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2101E617D8; Thu, 6 Jul 2023 00:44:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EAC35C433C7; Thu, 6 Jul 2023 00:44:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1688604282; bh=aEC6PCPk3DBXeBBrvw5oME0/w9hJPSVa0CwOwDzK5eA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ZHoiWE6ijdvrCAMom8HCoWZK5cb2gf0Tfw/24RivBzOPbokC20IXa0XpVfmEjlESo v1S4ZyPbcfhogeLVhTwMpVtIQxmEJRAzCVhwtL8qsIG17d9MqyIVNVzoc6D6HIxjeL EKQw1TOIKypxdrpKc9vqsOhVRC6DXGsMZBo0Hba0= Date: Wed, 5 Jul 2023 17:44:40 -0700 From: Andrew Morton To: Suren Baghdasaryan Cc: Peter Xu , David Hildenbrand , jirislaby@kernel.org, jacobly.alt@gmail.com, holger@applied-asynchrony.com, hdegoede@redhat.com, michel@lespinasse.org, jglisse@google.com, mhocko@suse.com, vbabka@suse.cz, hannes@cmpxchg.org, mgorman@techsingularity.net, dave@stgolabs.net, willy@infradead.org, liam.howlett@oracle.com, peterz@infradead.org, ldufour@linux.ibm.com, paulmck@kernel.org, mingo@redhat.com, will@kernel.org, luto@kernel.org, songliubraving@fb.com, dhowells@redhat.com, hughd@google.com, bigeasy@linutronix.de, kent.overstreet@linux.dev, punit.agrawal@bytedance.com, lstoakes@gmail.com, peterjung1337@gmail.com, rientjes@google.com, chriscli@google.com, axelrasmussen@google.com, joelaf@google.com, minchan@google.com, rppt@kernel.org, jannh@google.com, shakeelb@google.com, tatashin@google.com, edumazet@google.com, gthelen@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v3 2/2] mm: disable CONFIG_PER_VMA_LOCK until its fixed Message-Id: <20230705174440.9adb53f2e362056867135b84@linux-foundation.org> In-Reply-To: References: <20230705171213.2843068-1-surenb@google.com> <20230705171213.2843068-3-surenb@google.com> <3cdaa7d4-1293-3806-05ce-6b7fc4382458@redhat.com> <20230705172424.e505f5013bfdf44543d9c6be@linux-foundation.org> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Wed, 5 Jul 2023 17:32:09 -0700 Suren Baghdasaryan wrote: > On Wed, Jul 5, 2023 at 5:30 PM Suren Baghdasaryan wrote: > > > > On Wed, Jul 5, 2023 at 5:24 PM Andrew Morton wrote: > > > > > > On Wed, 5 Jul 2023 13:33:26 -0700 Suren Baghdasaryan wrote: > > > > > > > I was hoping we could re-enable VMA locks in 6.4 once we get more > > > > confirmations that the problem is gone. Is that not possible once the > > > > BROKEN dependency is merged? > > > > > > I think "no". By doing this we're effectively backporting a minor > > > performance optimization, which isn't a thing we'd normally do. > > > > In that case, maybe for 6.4 we send the fix and only disable it by > > default without marking BROKEN? That way we still have a way to enable > > it if desired? > > I'm preparing the next version with Liam's corrections. If the above > option I suggested is acceptable I can send a modified second patch > which would not have BROKEN dependency. I think just mark it broken and move on. At some later time we can consider backporting the fixes into 6.4.x and reenabling, but I don't think it's likely that we'll do this.