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author | Vincent Guittot <vincent.guittot@linaro.org> | 2018-02-13 11:31:18 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2018-03-09 07:59:22 +0100 |
commit | 1936c53ce8c8d4555e9ccad2dc8d98e0637b11f7 (patch) | |
tree | 5f3a736f7beb4717fd07d1af6c68399bbef20b88 /kernel/sched/fair.c | |
parent | f643ea2207010db26f17fca99db031bad87c8461 (diff) | |
download | linux-stable-1936c53ce8c8d4555e9ccad2dc8d98e0637b11f7.tar.gz linux-stable-1936c53ce8c8d4555e9ccad2dc8d98e0637b11f7.tar.bz2 linux-stable-1936c53ce8c8d4555e9ccad2dc8d98e0637b11f7.zip |
sched/fair: Reduce the periodic update duration
Instead of using the cfs_rq_is_decayed() which monitors all *_avg
and *_sum, we create a cfs_rq_has_blocked() which only takes care of
util_avg and load_avg. We are only interested by these 2 values which are
decaying faster than the *_sum so we can stop the periodic update earlier.
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: brendan.jackman@arm.com
Cc: dietmar.eggemann@arm.com
Cc: morten.rasmussen@foss.arm.com
Cc: valentin.schneider@arm.com
Link: http://lkml.kernel.org/r/1518517879-2280-3-git-send-email-vincent.guittot@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/fair.c')
-rw-r--r-- | kernel/sched/fair.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 78b06a0814d1..aad7c03dbad8 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7424,6 +7424,19 @@ static void attach_tasks(struct lb_env *env) rq_unlock(env->dst_rq, &rf); } +static inline bool cfs_rq_has_blocked(struct cfs_rq *cfs_rq) +{ + if (cfs_rq->avg.load_avg) + return true; + + if (cfs_rq->avg.util_avg) + return true; + + return false; +} + +#ifdef CONFIG_FAIR_GROUP_SCHED + static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq) { if (cfs_rq->load.weight) @@ -7441,8 +7454,6 @@ static inline bool cfs_rq_is_decayed(struct cfs_rq *cfs_rq) return true; } -#ifdef CONFIG_FAIR_GROUP_SCHED - static void update_blocked_averages(int cpu) { struct rq *rq = cpu_rq(cpu); @@ -7478,7 +7489,9 @@ static void update_blocked_averages(int cpu) */ if (cfs_rq_is_decayed(cfs_rq)) list_del_leaf_cfs_rq(cfs_rq); - else + + /* Don't need periodic decay once load/util_avg are null */ + if (cfs_rq_has_blocked(cfs_rq)) done = false; } @@ -7548,7 +7561,7 @@ static inline void update_blocked_averages(int cpu) update_cfs_rq_load_avg(cfs_rq_clock_task(cfs_rq), cfs_rq); #ifdef CONFIG_NO_HZ_COMMON rq->last_blocked_load_update_tick = jiffies; - if (cfs_rq_is_decayed(cfs_rq)) + if (!cfs_rq_has_blocked(cfs_rq)) rq->has_blocked_load = 0; #endif rq_unlock_irqrestore(rq, &rf); |