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=-11.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT 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 B2D49C433E9 for ; Wed, 17 Mar 2021 07:56:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8267D64FBD for ; Wed, 17 Mar 2021 07:56:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230448AbhCQHze (ORCPT ); Wed, 17 Mar 2021 03:55:34 -0400 Received: from out30-132.freemail.mail.aliyun.com ([115.124.30.132]:56783 "EHLO out30-132.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230358AbhCQHy6 (ORCPT ); Wed, 17 Mar 2021 03:54:58 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R351e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04426;MF=xlpang@linux.alibaba.com;NM=1;PH=DS;RN=15;SR=0;TI=SMTPD_---0USESt7q_1615967692; Received: from localhost(mailfrom:xlpang@linux.alibaba.com fp:SMTPD_---0USESt7q_1615967692) by smtp.aliyun-inc.com(127.0.0.1); Wed, 17 Mar 2021 15:54:52 +0800 From: Xunlei Pang To: Christoph Lameter , Christoph Lameter , Pekka Enberg , Vlastimil Babka , Roman Gushchin , Konstantin Khlebnikov , David Rientjes , Matthew Wilcox , Shu Ming , Andrew Morton Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Wen Yang , James Wang , Xunlei Pang Subject: [PATCH v4 0/3] mm/slub: Fix count_partial() problem Date: Wed, 17 Mar 2021 15:54:49 +0800 Message-Id: <1615967692-80524-1-git-send-email-xlpang@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org count_partial() can hold n->list_lock spinlock for quite long, which makes much trouble to the system. This series eliminate this problem. v1->v2: - Improved changelog and variable naming for PATCH 1~2. - PATCH3 adds per-cpu counter to avoid performance regression in concurrent __slab_free(). v2->v3: - Changed "page->inuse" to the safe "new.inuse", etc. - Used CONFIG_SLUB_DEBUG and CONFIG_SYSFS condition for new counters. - atomic_long_t -> unsigned long v3->v4: - introduced new CONFIG_SLUB_DEBUG_PARTIAL to give a chance to be enabled for production use. - Merged PATCH 4 into PATCH 1. [Testing] There seems might be a little performance impact under extreme __slab_free() concurrent calls according to my tests. On my 32-cpu 2-socket physical machine: Intel(R) Xeon(R) CPU E5-2650 v2 @ 2.60GHz 1) perf stat --null --repeat 10 -- hackbench 20 thread 20000 == original, no patched Performance counter stats for 'hackbench 20 thread 20000' (10 runs): 24.536050899 seconds time elapsed ( +- 0.24% ) Performance counter stats for 'hackbench 20 thread 20000' (10 runs): 24.588049142 seconds time elapsed ( +- 0.35% ) == patched with patch1~4 Performance counter stats for 'hackbench 20 thread 20000' (10 runs): 24.670892273 seconds time elapsed ( +- 0.29% ) Performance counter stats for 'hackbench 20 thread 20000' (10 runs): 24.746755689 seconds time elapsed ( +- 0.21% ) 2) perf stat --null --repeat 10 -- hackbench 32 thread 20000 == original, no patched Performance counter stats for 'hackbench 32 thread 20000' (10 runs): 39.784911855 seconds time elapsed ( +- 0.14% ) Performance counter stats for 'hackbench 32 thread 20000' (10 runs): 39.868687608 seconds time elapsed ( +- 0.19% ) == patched with patch1~4 Performance counter stats for 'hackbench 32 thread 20000' (10 runs): 39.681273015 seconds time elapsed ( +- 0.21% ) Performance counter stats for 'hackbench 32 thread 20000' (10 runs): 39.681238459 seconds time elapsed ( +- 0.09% ) Xunlei Pang (3): mm/slub: Introduce two counters for partial objects percpu: Export per_cpu_sum() mm/slub: Get rid of count_partial() include/linux/percpu-defs.h | 10 ++++ init/Kconfig | 13 +++++ kernel/locking/percpu-rwsem.c | 10 ---- mm/slab.h | 6 ++ mm/slub.c | 129 +++++++++++++++++++++++++++++------------- 5 files changed, 120 insertions(+), 48 deletions(-) -- 1.8.3.1