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| author | Vincent Guittot <vincent.guittot@linaro.org> | 2023-10-09 12:36:16 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2023-10-09 12:59:48 +0200 |
| commit | 7bc263840bc3377186cb06b003ac287bb2f18ce2 (patch) | |
| tree | 1b1e2ea78cc73c98cb56ebdd1c7add108f157c35 /kernel/sched/deadline.c | |
| parent | 089768dfeb3ab294f9ab6a1f2462001f0f879fbb (diff) | |
| download | linux-7bc263840bc3377186cb06b003ac287bb2f18ce2.tar.gz linux-7bc263840bc3377186cb06b003ac287bb2f18ce2.tar.bz2 linux-7bc263840bc3377186cb06b003ac287bb2f18ce2.zip | |
sched/topology: Consolidate and clean up access to a CPU's max compute capacity
Remove the rq::cpu_capacity_orig field and use arch_scale_cpu_capacity()
instead.
The scheduler uses 3 methods to get access to a CPU's max compute capacity:
- arch_scale_cpu_capacity(cpu) which is the default way to get a CPU's capacity.
- cpu_capacity_orig field which is periodically updated with
arch_scale_cpu_capacity().
- capacity_orig_of(cpu) which encapsulates rq->cpu_capacity_orig.
There is no real need to save the value returned by arch_scale_cpu_capacity()
in struct rq. arch_scale_cpu_capacity() returns:
- either a per_cpu variable.
- or a const value for systems which have only one capacity.
Remove rq::cpu_capacity_orig and use arch_scale_cpu_capacity() everywhere.
No functional changes.
Some performance tests on Arm64:
- small SMP device (hikey): no noticeable changes
- HMP device (RB5): hackbench shows minor improvement (1-2%)
- large smp (thx2): hackbench and tbench shows minor improvement (1%)
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/20231009103621.374412-2-vincent.guittot@linaro.org
Diffstat (limited to 'kernel/sched/deadline.c')
| -rw-r--r-- | kernel/sched/deadline.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index d98408a274e5..7039a8d5ae9b 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -132,7 +132,7 @@ static inline unsigned long __dl_bw_capacity(const struct cpumask *mask) int i; for_each_cpu_and(i, mask, cpu_active_mask) - cap += capacity_orig_of(i); + cap += arch_scale_cpu_capacity(i); return cap; } @@ -144,7 +144,7 @@ static inline unsigned long __dl_bw_capacity(const struct cpumask *mask) static inline unsigned long dl_bw_capacity(int i) { if (!sched_asym_cpucap_active() && - capacity_orig_of(i) == SCHED_CAPACITY_SCALE) { + arch_scale_cpu_capacity(i) == SCHED_CAPACITY_SCALE) { return dl_bw_cpus(i) << SCHED_CAPACITY_SHIFT; } else { RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(), |