sched/fair: Use non-atomic cpumask_{set,clear}_cpu()

The cpumasks updated here are not subject to concurrency and using
atomic bitops for them is pointless and expensive. Use the non-atomic
variants instead.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Link: http://lkml.kernel.org/r/2e2a10f84b9049a81eef94ed6d5989447c21e34a.1549963617.git.viresh.kumar@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 8abd1c2714997efdda48762aaf0be5f4c6a7e77d..8213ff6e365d1699e4dae34ce1adfb385d82fec9 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6097,7 +6097,7 @@ static int select_idle_core(struct task_struct *p, struct sched_domain *sd, int
                bool idle = true;
 
                for_each_cpu(cpu, cpu_smt_mask(core)) {
-                       cpumask_clear_cpu(cpu, cpus);
+                       __cpumask_clear_cpu(cpu, cpus);
                        if (!available_idle_cpu(cpu))
                                idle = false;
                }
@@ -9105,7 +9105,7 @@ more_balance:
                if ((env.flags & LBF_DST_PINNED) && env.imbalance > 0) {
 
                        /* Prevent to re-select dst_cpu via env's CPUs */
-                       cpumask_clear_cpu(env.dst_cpu, env.cpus);
+                       __cpumask_clear_cpu(env.dst_cpu, env.cpus);
 
                        env.dst_rq       = cpu_rq(env.new_dst_cpu);
                        env.dst_cpu      = env.new_dst_cpu;
@@ -9132,7 +9132,7 @@ more_balance:
 
                /* All tasks on this runqueue were pinned by CPU affinity */
                if (unlikely(env.flags & LBF_ALL_PINNED)) {
-                       cpumask_clear_cpu(cpu_of(busiest), cpus);
+                       __cpumask_clear_cpu(cpu_of(busiest), cpus);
                        /*
                         * Attempting to continue load balancing at the current
                         * sched_domain level only makes sense if there are

diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c
index 81faddba9e2011e2dff9a83f64e28fcc932e81c2..b02d148e767273c3a2641b4c66b9f0d24ea6e9ee 100644 (file)
--- a/kernel/sched/isolation.c
+++ b/kernel/sched/isolation.c
@@ -80,7 +80,7 @@ static int __init housekeeping_setup(char *str, enum hk_flags flags)
                cpumask_andnot(housekeeping_mask,
                               cpu_possible_mask, non_housekeeping_mask);
                if (cpumask_empty(housekeeping_mask))
-                       cpumask_set_cpu(smp_processor_id(), housekeeping_mask);
+                       __cpumask_set_cpu(smp_processor_id(), housekeeping_mask);
        } else {
                cpumask_var_t tmp;