lkml.org 
[lkml]   [2021]   [Mar]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip: sched/core] sched/fair: Reduce the window for duplicated update
The following commit has been merged into the sched/core branch of tip:

Commit-ID: 839ffb99d94f930fecbdee2fdfb883b10c30326b
Gitweb: https://git.kernel.org/tip/839ffb99d94f930fecbdee2fdfb883b10c30326b
Author: Vincent Guittot <vincent.guittot@linaro.org>
AuthorDate: Wed, 24 Feb 2021 14:30:07 +01:00
Committer: Peter Zijlstra <peterz@infradead.org>
CommitterDate: Mon, 01 Mar 2021 18:17:25 +01:00

sched/fair: Reduce the window for duplicated update

Start to update last_blocked_load_update_tick to reduce the possibility
of another cpu starting the update one more time

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20210224133007.28644-8-vincent.guittot@linaro.org
---
kernel/sched/fair.c | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e87e1b3..f1b55f9 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -7852,16 +7852,20 @@ static inline bool others_have_blocked(struct rq *rq)
return false;
}

-static inline void update_blocked_load_status(struct rq *rq, bool has_blocked)
+static inline void update_blocked_load_tick(struct rq *rq)
{
- rq->last_blocked_load_update_tick = jiffies;
+ WRITE_ONCE(rq->last_blocked_load_update_tick, jiffies);
+}

+static inline void update_blocked_load_status(struct rq *rq, bool has_blocked)
+{
if (!has_blocked)
rq->has_blocked_load = 0;
}
#else
static inline bool cfs_rq_has_blocked(struct cfs_rq *cfs_rq) { return false; }
static inline bool others_have_blocked(struct rq *rq) { return false; }
+static inline void update_blocked_load_tick(struct rq *rq) {}
static inline void update_blocked_load_status(struct rq *rq, bool has_blocked) {}
#endif

@@ -8022,6 +8026,7 @@ static void update_blocked_averages(int cpu)
struct rq_flags rf;

rq_lock_irqsave(rq, &rf);
+ update_blocked_load_tick(rq);
update_rq_clock(rq);

decayed |= __update_blocked_others(rq, &done);
@@ -8363,7 +8368,7 @@ static bool update_nohz_stats(struct rq *rq)
if (!cpumask_test_cpu(cpu, nohz.idle_cpus_mask))
return false;

- if (!time_after(jiffies, rq->last_blocked_load_update_tick))
+ if (!time_after(jiffies, READ_ONCE(rq->last_blocked_load_update_tick)))
return true;

update_blocked_averages(cpu);
\
 
 \ /
  Last update: 2021-03-02 16:29    [W:0.221 / U:0.024 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site