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=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,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 026DDC4338F for ; Sun, 25 Jul 2021 14:17:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DAEB460EB4 for ; Sun, 25 Jul 2021 14:17:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230260AbhGYNgs (ORCPT ); Sun, 25 Jul 2021 09:36:48 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:37410 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231210AbhGYNgq (ORCPT ); Sun, 25 Jul 2021 09:36:46 -0400 Received: from imap1.suse-dmz.suse.de (imap1.suse-dmz.suse.de [192.168.254.73]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 825E421DD5; Sun, 25 Jul 2021 14:17:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1627222635; h=from:from:reply-to: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=s8ld6eWOXWKab5mW3GS50lPqoO9veaqwntkiFTmeRvI=; b=PkFWRCgX5fFQpPytMRH8aSjiRGDCAQQ9DZwtgeg9/3knLpQsknGrQm693Ujt61SP+4MCzt bDPBuHEAMnMMdPrC7C9FyP+F1J3aWQUA2qCI0SpmRcz0YsF9CeG1wvoh+2ksrbBkXn0Xbj SH1J4oVwQB9LO5k2aq/2vyic2pbPnoo= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1627222635; h=from:from:reply-to: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=s8ld6eWOXWKab5mW3GS50lPqoO9veaqwntkiFTmeRvI=; b=Myb4ls9NRtS2ogZ4/T7qnDB5Qz2c62ZVdCE8T9cunPvyhljOje1eKrHnM7FkY2IzAi7jXb 5rjTNIuvlIPL11Cw== Received: from imap1.suse-dmz.suse.de (imap1.suse-dmz.suse.de [192.168.254.73]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap1.suse-dmz.suse.de (Postfix) with ESMTPS id 5C37A13277; Sun, 25 Jul 2021 14:17:15 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap1.suse-dmz.suse.de with ESMTPSA id IL0aFWty/WD9FgAAGKfGzw (envelope-from ); Sun, 25 Jul 2021 14:17:15 +0000 Subject: Re: [rfc/patch] mm/slub: restore/expand unfreeze_partials() local exclusion scope To: Mike Galbraith , Thomas Gleixner , LKML Cc: linux-rt-users@vger.kernel.org, Mel Gorman , Sebastian Andrzej Siewior References: <87tul5p2fa.ffs@nanos.tec.linutronix.de> <8c0e0c486056b5185b58998f2cce62619ed3f05c.camel@gmx.de> <878s2fnv79.ffs@nanos.tec.linutronix.de> <6c0e20dd84084036d5068e445746c3ed7e82ec4b.camel@gmx.de> <7431ceb9761c566cf2d1f6f263247acd8d38c4b5.camel@gmx.de> <240f104fc6757d8c38fa01342511eda931632d5a.camel@gmx.de> <69da2ecd-a797-e264-fbfa-13108dc7a573@suse.cz> <84a7bd02cf109c6a5a8c7cc2bfc2898cb98270aa.camel@gmx.de> <5be1a703-9a0a-4115-1d69-634e5e8ecefd@suse.cz> From: Vlastimil Babka Message-ID: <76dedfc3-0497-1776-d006-486b9bfd88da@suse.cz> Date: Sun, 25 Jul 2021 16:16:42 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/25/21 4:09 PM, Mike Galbraith wrote: > On Sat, 2021-07-24 at 00:39 +0200, Vlastimil Babka wrote: >> >> If not, then I would expect this to work (I don't think they ever nest >> in the opposite order, also lockdep should tell us instead of >> -ENOBOOT?), but might be missing something... > > Yeah, like #ifndef CONFIG_PREMPT_RT at the bottom of the loop that our > useless damn eyeballs auto-correct instead of reporting :) Well doh, good catch. Hope fixing that helps then? I've so far convinced myself that the full patch will be needed - in my theory the ->partial cmpxchg in put_cpu_partial() itself can race with assignment in ___slab_alloc() in a way that will not cause crashes, but will leak slab pages. > -Mike >