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 18612C61DA3 for ; Fri, 3 Mar 2023 22:36:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232630AbjCCWgy (ORCPT ); Fri, 3 Mar 2023 17:36:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42528 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232744AbjCCWgT (ORCPT ); Fri, 3 Mar 2023 17:36:19 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E002932513 for ; Fri, 3 Mar 2023 14:34:09 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 3067CB81A2E for ; Fri, 3 Mar 2023 22:32:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AA33AC433EF; Fri, 3 Mar 2023 22:32:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1677882762; bh=ElQSyJlCXmUXSKBFIN4iBBZ5P4k9q+eHP9wuDUm7nTo=; h=Date:To:From:Subject:From; b=BDqssus7jcYvx+J/tvpXnzVt4K1Q06CFo2a6II2BA3RAFR2ZEeOfKe+NEb29lG9q6 /+xBA7p9TCmSiqbFkYzb2txkuEmlb3uuuML9OXqlJHNLpwMtlFhA+XNdcFlY3iwkpf k/Q4UO4X9uiABJL4y3Gi5SagaAv6ICuTTkMcN2kI= Date: Fri, 03 Mar 2023 14:32:42 -0800 To: mm-commits@vger.kernel.org, tglx@linutronix.de, peterx@redhat.com, mingo@elte.hu, linux@armlinux.org.uk, hpa@zytor.com, hca@linux.ibm.com, frederic@kernel.org, david@redhat.com, cl@linux.com, chenhuacai@kernel.org, atomlin@atomlin.com, mtosatti@redhat.com, akpm@linux-foundation.org From: Andrew Morton Subject: + mm-vmstat-use-xchg-in-cpu_vm_stats_fold.patch added to mm-unstable branch Message-Id: <20230303223242.AA33AC433EF@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: mm/vmstat: use xchg in cpu_vm_stats_fold has been added to the -mm mm-unstable branch. Its filename is mm-vmstat-use-xchg-in-cpu_vm_stats_fold.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vmstat-use-xchg-in-cpu_vm_stats_fold.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Marcelo Tosatti Subject: mm/vmstat: use xchg in cpu_vm_stats_fold Date: Fri, 03 Mar 2023 16:58:50 -0300 In preparation to switch vmstat shepherd to flush per-CPU counters remotely, use xchg instead of a pair of read/write instructions. Link: https://lkml.kernel.org/r/20230303195908.977788434@redhat.com Signed-off-by: Marcelo Tosatti Cc: Aaron Tomlin Cc: Christoph Lameter Cc: David Hildenbrand Cc: Frederic Weisbecker Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Huacai Chen Cc: Ingo Molnar Cc: Peter Xu Cc: "Russell King (Oracle)" Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- --- a/mm/vmstat.c~mm-vmstat-use-xchg-in-cpu_vm_stats_fold +++ a/mm/vmstat.c @@ -883,7 +883,7 @@ static int refresh_cpu_vm_stats(void) } /* - * Fold the data for an offline cpu into the global array. + * Fold the data for a cpu into the global array. * There cannot be any access by the offline cpu and therefore * synchronization is simplified. */ @@ -904,8 +904,7 @@ void cpu_vm_stats_fold(int cpu) if (pzstats->vm_stat_diff[i]) { int v; - v = pzstats->vm_stat_diff[i]; - pzstats->vm_stat_diff[i] = 0; + v = xchg(&pzstats->vm_stat_diff[i], 0); atomic_long_add(v, &zone->vm_stat[i]); global_zone_diff[i] += v; } @@ -915,8 +914,7 @@ void cpu_vm_stats_fold(int cpu) if (pzstats->vm_numa_event[i]) { unsigned long v; - v = pzstats->vm_numa_event[i]; - pzstats->vm_numa_event[i] = 0; + v = xchg(&pzstats->vm_numa_event[i], 0); zone_numa_event_add(v, zone, i); } } @@ -932,8 +930,7 @@ void cpu_vm_stats_fold(int cpu) if (p->vm_node_stat_diff[i]) { int v; - v = p->vm_node_stat_diff[i]; - p->vm_node_stat_diff[i] = 0; + v = xchg(&p->vm_node_stat_diff[i], 0); atomic_long_add(v, &pgdat->vm_stat[i]); global_node_diff[i] += v; } _ Patches currently in -mm which might be from mtosatti@redhat.com are mm-vmstat-remove-remote-node-draining.patch this_cpu_cmpxchg-arm64-switch-this_cpu_cmpxchg-to-locked-add-_local-function.patch this_cpu_cmpxchg-loongarch-switch-this_cpu_cmpxchg-to-locked-add-_local-function.patch this_cpu_cmpxchg-s390-switch-this_cpu_cmpxchg-to-locked-add-_local-function.patch this_cpu_cmpxchg-x86-switch-this_cpu_cmpxchg-to-locked-add-_local-function.patch add-this_cpu_cmpxchg_local-and-asm-generic-definitions.patch convert-this_cpu_cmpxchg-users-to-this_cpu_cmpxchg_local.patch mm-vmstat-switch-counter-modification-to-cmpxchg.patch mm-vmstat-use-xchg-in-cpu_vm_stats_fold.patch mm-vmstat-switch-vmstat-shepherd-to-flush-per-cpu-counters-remotely.patch mm-vmstat-refresh-stats-remotely-instead-of-via-work-item.patch