[PATCH v5 2/9] task_isolation: vmstat: add vmstat_idle function
From: Alex Belits <hidden>
Date: 2020-11-23 17:57:42
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> This function checks to see if a vmstat worker is not running, and the vmstat diffs don't require an update. The function is called from the task-isolation code to see if we need to actually do some work to quiet vmstat. Signed-off-by: Chris Metcalf <redacted> Signed-off-by: Alex Belits <redacted> --- include/linux/vmstat.h | 2 ++ mm/vmstat.c | 10 ++++++++++ 2 files changed, 12 insertions(+)
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 300ce6648923..24392a957cfc 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h@@ -285,6 +285,7 @@ extern void __dec_node_state(struct pglist_data *, enum node_stat_item); void quiet_vmstat(void); void quiet_vmstat_sync(void); +bool vmstat_idle(void); void cpu_vm_stats_fold(int cpu); void refresh_zone_stat_thresholds(void);
@@ -393,6 +394,7 @@ 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 bool vmstat_idle(void) { return true; } static inline void drain_zonestat(struct zone *zone, struct per_cpu_pageset *pset) { }
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 43999caf47a4..5b0ad7ed65f7 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c@@ -1945,6 +1945,16 @@ void quiet_vmstat_sync(void) refresh_cpu_vm_stats(false); } +/* + * Report on whether vmstat processing is quiesced on the core currently: + * no vmstat worker running and no vmstat updates to perform. + */ +bool vmstat_idle(void) +{ + return !delayed_work_pending(this_cpu_ptr(&vmstat_work)) && + !need_update(smp_processor_id()); +} + /* * Shepherd worker thread that checks the * differentials of processors that have their worker
--
2.20.1