From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752734AbcGNUwm (ORCPT ); Thu, 14 Jul 2016 16:52:42 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:49068 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752266AbcGNUsf (ORCPT ); Thu, 14 Jul 2016 16:48:35 -0400 From: Chris Metcalf To: Gilad Ben Yossef , Steven Rostedt , Ingo Molnar , Peter Zijlstra , Andrew Morton , Rik van Riel , Tejun Heo , Frederic Weisbecker , Thomas Gleixner , "Paul E. McKenney" , Christoph Lameter , Viresh Kumar , Catalin Marinas , Will Deacon , Andy Lutomirski , Michal Hocko , linux-kernel@vger.kernel.org Cc: Chris Metcalf Subject: [PATCH v13 01/12] vmstat: add quiet_vmstat_sync function Date: Thu, 14 Jul 2016 16:48:08 -0400 Message-Id: <1468529299-27929-2-git-send-email-cmetcalf@mellanox.com> X-Mailer: git-send-email 2.7.2 In-Reply-To: <1468529299-27929-1-git-send-email-cmetcalf@mellanox.com> References: <1468529299-27929-1-git-send-email-cmetcalf@mellanox.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In commit f01f17d3705b ("mm, vmstat: make quiet_vmstat lighter") the quiet_vmstat() function became asynchronous, in the sense that the vmstat work was still scheduled to run on the core when the function returned. For task isolation, we need a synchronous version of the function that guarantees that the vmstat worker will not run on the core on return from the function. Add a quiet_vmstat_sync() function with that semantic. Signed-off-by: Chris Metcalf --- include/linux/vmstat.h | 2 ++ mm/vmstat.c | 9 +++++++++ 2 files changed, 11 insertions(+) diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h index d2da8e053210..0d96b6b2079d 100644 --- a/include/linux/vmstat.h +++ b/include/linux/vmstat.h @@ -188,6 +188,7 @@ extern void dec_zone_state(struct zone *, enum zone_stat_item); extern void __dec_zone_state(struct zone *, enum zone_stat_item); void quiet_vmstat(void); +void quiet_vmstat_sync(void); void cpu_vm_stats_fold(int cpu); void refresh_zone_stat_thresholds(void); @@ -253,6 +254,7 @@ static inline void __dec_zone_page_state(struct page *page, static inline void refresh_zone_stat_thresholds(void) { } static inline void cpu_vm_stats_fold(int cpu) { } static inline void quiet_vmstat(void) { } +static inline void quiet_vmstat_sync(void) { } static inline void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset) { } diff --git a/mm/vmstat.c b/mm/vmstat.c index cb2a67bb4158..945af7ab624e 100644 --- a/mm/vmstat.c +++ b/mm/vmstat.c @@ -1483,6 +1483,15 @@ void quiet_vmstat(void) } /* + * Synchronously quiet vmstat so the work is guaranteed not to run on return. + */ +void quiet_vmstat_sync(void) +{ + cancel_delayed_work_sync(this_cpu_ptr(&vmstat_work)); + refresh_cpu_vm_stats(false); +} + +/* * Shepherd worker thread that checks the * differentials of processors that have their worker * threads for vm statistics updates disabled because of -- 2.7.2