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 C046AC4320A for ; Wed, 4 Aug 2021 12:05:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 41D2260F22 for ; Wed, 4 Aug 2021 12:05:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 41D2260F22 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=techsingularity.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id A95558D005E; Wed, 4 Aug 2021 08:05:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A45C88D002D; Wed, 4 Aug 2021 08:05:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 95B9B8D005E; Wed, 4 Aug 2021 08:05:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0140.hostedemail.com [216.40.44.140]) by kanga.kvack.org (Postfix) with ESMTP id 7BFC58D002D for ; Wed, 4 Aug 2021 08:05:27 -0400 (EDT) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 2DD2418023EDE for ; Wed, 4 Aug 2021 12:05:27 +0000 (UTC) X-FDA: 78437268294.12.3ED81B8 Received: from outbound-smtp25.blacknight.com (outbound-smtp25.blacknight.com [81.17.249.193]) by imf19.hostedemail.com (Postfix) with ESMTP id 6D77CB00BCAA for ; Wed, 4 Aug 2021 12:05:26 +0000 (UTC) Received: from mail.blacknight.com (pemlinmail02.blacknight.ie [81.17.254.11]) by outbound-smtp25.blacknight.com (Postfix) with ESMTPS id C002BCAD51 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) X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 6D77CB00BCAA Authentication-Results: imf19.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf19.hostedemail.com: domain of mgorman@techsingularity.net designates 81.17.249.193 as permitted sender) smtp.mailfrom=mgorman@techsingularity.net X-Stat-Signature: 8op3rchznphtk6rj1accayjjumt39z8d X-HE-Tag: 1628078726-320703 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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