[PATCH v2 01/12] task_isolation: vmstat: add quiet_vmstat_sync function
From: Alex Belits <hidden>
Date: 2020-03-08 03:44:57
Also in:
linux-api, linux-arch, linux-arm-kernel, lkml
Subsystem:
memory management, memory management - core, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Linus Torvalds
From: Chris Metcalf <redacted>
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 <redacted>
Signed-off-by: Alex Belits <redacted>
---
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 292485f3d24d..2bc5e85f2514 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h@@ -270,6 +270,7 @@ extern void __dec_zone_state(struct zone *, enum zone_stat_item); extern void __dec_node_state(struct pglist_data *, enum node_stat_item); void quiet_vmstat(void); +void quiet_vmstat_sync(void); void cpu_vm_stats_fold(int cpu); void refresh_zone_stat_thresholds(void);
@@ -372,6 +373,7 @@ static inline void __dec_node_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 78d53378db99..1fa0b2d04afa 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c@@ -1870,6 +1870,15 @@ void quiet_vmstat(void) refresh_cpu_vm_stats(false); } +/* + * 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
--
2.20.1