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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 9CF2CC4338F for ; Wed, 4 Aug 2021 12:05:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6C94060F41 for ; Wed, 4 Aug 2021 12:05:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237956AbhHDMFj (ORCPT ); Wed, 4 Aug 2021 08:05:39 -0400 Received: from outbound-smtp01.blacknight.com ([81.17.249.7]:49513 "EHLO outbound-smtp01.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234765AbhHDMFi (ORCPT ); Wed, 4 Aug 2021 08:05:38 -0400 Received: from mail.blacknight.com (pemlinmail02.blacknight.ie [81.17.254.11]) by outbound-smtp01.blacknight.com (Postfix) with ESMTPS id BE0F3C4A88 for ; Wed, 4 Aug 2021 13:05:24 +0100 (IST) Received: (qmail 17282 invoked from network); 4 Aug 2021 12:05:24 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.17.255]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 4 Aug 2021 12:05:24 -0000 Date: Wed, 4 Aug 2021 13:05:22 +0100 From: Mel Gorman To: Vlastimil Babka Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Christoph Lameter , David Rientjes , Pekka Enberg , Joonsoo Kim , Mike Galbraith , Sebastian Andrzej Siewior , Thomas Gleixner , Jesper Dangaard Brouer , Jann Horn Subject: Re: [PATCH v3 00/35] SLUB: reduce irq disabled scope and make it RT compatible Message-ID: <20210804120522.GD6464@techsingularity.net> References: <20210729132132.19691-1-vbabka@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20210729132132.19691-1-vbabka@suse.cz> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 29, 2021 at 03:20:57PM +0200, Vlastimil Babka wrote: > Changes since v2 [5]: > * Rebase to 5.14-rc3 > * A number of fixes to the RT parts, big thanks to Mike Galbraith for testing > and debugging! > * The largest fix is to protect kmem_cache_cpu->partial by local_lock instead > of cmpxchg tricks, which are insufficient on RT. To avoid divergence > between RT and !RT, just do it everywhere. Affected mainly patch 25 and a > new patch 33. This also addresses a theoretical race raised earlier by Jann > Horn. > * Smaller fixes reported by Sebastian Andrzej Siewior and Cyrill Gorcunov > > Changes since RFC v1 [1]: > * Addressed feedback from Christoph and Mel, added their acks. > * Finished RT conversion, adopting 2 patches from the RT tree. > * The local_lock conversion has to sacrifice lockless fathpaths on PREEMPT_RT > * Added some more cleanup patches to the front. > > This series was initially inspired by Mel's pcplist local_lock rewrite, and > also interest to better understand SLUB's locking and the new primitives and RT > variants and implications. It should make SLUB more preemption-friendly, > especially for RT, hopefully without noticeable regressions, as the fast paths > are not affected. > > Series is based on 5.14-rc3 and also available as a git branch: > https://git.kernel.org/pub/scm/linux/kernel/git/vbabka/linux.git/log/?h=slub-local-lock-v3r1 > FWIW, I ran a corrected version of this series through a few tests. Some small gains, no major regressions in terms of performance on a !PREEMPT_RT configuration across 6 different machines. -- Mel Gorman SUSE Labs