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| author |   Peter Zijlstra <peterz@infradead.org> | 2019-02-27 10:27:58 +0100 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2019-06-17 12:43:43 +0200 |
| commit | 8dc2d993cf1aea578d947e34ea2d5c6ffd1644e4 (patch) | |
| tree | d6eaa5e880f797ca01c677175df65031a90ca032 /kernel/sched | |
| parent | x86/percpu, x86/irq: Relax {set,get}_irq_regs() (diff) | |
| download | linux-dev-8dc2d993cf1aea578d947e34ea2d5c6ffd1644e4.tar.xz linux-dev-8dc2d993cf1aea578d947e34ea2d5c6ffd1644e4.zip | |
x86/percpu, sched/fair: Avoid local_clock()
Nadav reported that code-gen changed because of the this_cpu_*()
constraints, avoid this for select_idle_cpu() because that runs with
preemption (and IRQs) disabled anyway.
Reported-by: Nadav Amit <nadav.amit@gmail.com>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/fair.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index f35930f5e528..8591529e1753 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6189,6 +6189,7 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t u64 time, cost; s64 delta; int cpu, nr = INT_MAX; + int this = smp_processor_id(); this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc)); if (!this_sd) @@ -6212,7 +6213,7 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t nr = 4; } - time = local_clock(); + time = cpu_clock(this); for_each_cpu_wrap(cpu, sched_domain_span(sd), target) { if (!--nr) @@ -6223,7 +6224,7 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t break; } - time = local_clock() - time; + time = cpu_clock(this) - time; cost = this_sd->avg_scan_cost; delta = (s64)(time - cost) / 8; this_sd->avg_scan_cost += delta; |