diff options
Diffstat (limited to 'kernel/sched/fair.c')
| -rw-r--r-- | kernel/sched/fair.c | 53 |
1 files changed, 5 insertions, 48 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index c242944..7a68c63 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -5310,43 +5310,6 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) return shallowest_idle_cpu != -1 ? shallowest_idle_cpu : least_loaded_cpu; } -/* - * Implement a for_each_cpu() variant that starts the scan at a given cpu - * (@start), and wraps around. - * - * This is used to scan for idle CPUs; such that not all CPUs looking for an - * idle CPU find the same CPU. The down-side is that tasks tend to cycle - * through the LLC domain. - * - * Especially tbench is found sensitive to this. - */ - -static int cpumask_next_wrap(int n, const struct cpumask *mask, int start, int *wrapped) -{ - int next; - -again: - next = find_next_bit(cpumask_bits(mask), nr_cpumask_bits, n+1); - - if (*wrapped) { - if (next >= start) - return nr_cpumask_bits; - } else { - if (next >= nr_cpumask_bits) { - *wrapped = 1; - n = -1; - goto again; - } - } - - return next; -} - -#define for_each_cpu_wrap(cpu, mask, start, wrap) \ - for ((wrap) = 0, (cpu) = (start)-1; \ - (cpu) = cpumask_next_wrap((cpu), (mask), (start), &(wrap)), \ - (cpu) < nr_cpumask_bits; ) - #ifdef CONFIG_SCHED_SMT static inline void set_idle_cores(int cpu, int val) @@ -5376,7 +5339,7 @@ static inline bool test_idle_cores(int cpu, bool def) * Since SMT siblings share all cache levels, inspecting this limited remote * state should be fairly cheap. */ -void __update_idle_core(struct rq *rq) +void update_idle_core(struct rq *rq) { int core = cpu_of(rq); int cpu; @@ -5406,17 +5369,14 @@ unlock: static int select_idle_core(struct task_struct *p, struct sched_domain *sd, int target) { struct cpumask *cpus = this_cpu_cpumask_var_ptr(select_idle_mask); - int core, cpu, wrap; - - if (!static_branch_likely(&sched_smt_present)) - return -1; + int core, cpu; if (!test_idle_cores(target, false)) return -1; cpumask_and(cpus, sched_domain_span(sd), tsk_cpus_allowed(p)); - for_each_cpu_wrap(core, cpus, target, wrap) { + for_each_cpu_wrap(core, cpus, target) { bool idle = true; for_each_cpu(cpu, cpu_smt_mask(core)) { @@ -5444,9 +5404,6 @@ static int select_idle_smt(struct task_struct *p, struct sched_domain *sd, int t { int cpu; - if (!static_branch_likely(&sched_smt_present)) - return -1; - for_each_cpu(cpu, cpu_smt_mask(target)) { if (!cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) continue; @@ -5482,7 +5439,7 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t u64 avg_cost, avg_idle = this_rq()->avg_idle; u64 time, cost; s64 delta; - int cpu, wrap; + int cpu; this_sd = rcu_dereference(*this_cpu_ptr(&sd_llc)); if (!this_sd) @@ -5499,7 +5456,7 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t time = local_clock(); - for_each_cpu_wrap(cpu, sched_domain_span(sd), target, wrap) { + for_each_cpu_wrap(cpu, sched_domain_span(sd), target) { if (!cpumask_test_cpu(cpu, tsk_cpus_allowed(p))) continue; if (idle_cpu(cpu)) |