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| author | Peter Zijlstra <peterz@infradead.org> | 2018-02-13 16:54:17 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-03-09 07:59:22 +0100 |
| commit | 63928384faefba1b31c3bb77361965715a9fc71c (patch) | |
| tree | b51ab9e5fbf6e597cbb4c99514201d245f918e02 /kernel/sched/fair.c | |
| parent | sched/fair: Reduce the periodic update duration (diff) | |
| download | linux-63928384faefba1b31c3bb77361965715a9fc71c.tar.xz linux-63928384faefba1b31c3bb77361965715a9fc71c.zip | |
sched/nohz: Optimize nohz_idle_balance()
Avoid calling update_blocked_averages() when it does not in fact have
any by re-using/extending update_nohz_stats().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/fair.c')
| -rw-r--r-- | kernel/sched/fair.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index aad7c03dbad8..5c357561db5d 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7898,7 +7898,7 @@ group_type group_classify(struct sched_group *group, return group_other; } -static bool update_nohz_stats(struct rq *rq) +static bool update_nohz_stats(struct rq *rq, bool force) { #ifdef CONFIG_NO_HZ_COMMON unsigned int cpu = rq->cpu; @@ -7909,7 +7909,7 @@ 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 (!force && !time_after(jiffies, rq->last_blocked_load_update_tick)) return true; update_blocked_averages(cpu); @@ -7942,7 +7942,7 @@ static inline void update_sg_lb_stats(struct lb_env *env, for_each_cpu_and(i, sched_group_span(group), env->cpus) { struct rq *rq = cpu_rq(i); - if ((env->flags & LBF_NOHZ_STATS) && update_nohz_stats(rq)) + if ((env->flags & LBF_NOHZ_STATS) && update_nohz_stats(rq, false)) env->flags |= LBF_NOHZ_AGAIN; /* Bias balancing toward CPUs of our domain: */ @@ -9552,8 +9552,7 @@ static bool nohz_idle_balance(struct rq *this_rq, enum cpu_idle_type idle) rq = cpu_rq(balance_cpu); - update_blocked_averages(rq->cpu); - has_blocked_load |= rq->has_blocked_load; + has_blocked_load |= update_nohz_stats(rq, true); /* * If time for next balance is due, |