diff options
author | Ingo Molnar <mingo@kernel.org> | 2018-12-03 11:42:17 +0100 |
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committer | Ingo Molnar <mingo@kernel.org> | 2018-12-03 11:42:17 +0100 |
commit | 5f675231e456cb599b283f8361f01cf34b0617df (patch) | |
tree | afb2bdfd6fdbb18336146f41ba7659120a5ff9d2 /kernel/sched/core.c | |
parent | 3e184501083c38fa091f640acb13af17a21fd228 (diff) | |
parent | 2595646791c319cadfdbf271563aac97d0843dc7 (diff) |
Merge tag 'v4.20-rc5' into sched/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/core.c')
-rw-r--r-- | kernel/sched/core.c | 53 |
1 files changed, 24 insertions, 29 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 5afb868f7339..8050f266751a 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2881,6 +2881,18 @@ unsigned long long nr_context_switches(void) } /* + * Consumers of these two interfaces, like for example the cpuidle menu + * governor, are using nonsensical data. Preferring shallow idle state selection + * for a CPU that has IO-wait which might not even end up running the task when + * it does become runnable. + */ + +unsigned long nr_iowait_cpu(int cpu) +{ + return atomic_read(&cpu_rq(cpu)->nr_iowait); +} + +/* * IO-wait accounting, and how its mostly bollocks (on SMP). * * The idea behind IO-wait account is to account the idle time that we could @@ -2915,31 +2927,11 @@ unsigned long nr_iowait(void) unsigned long i, sum = 0; for_each_possible_cpu(i) - sum += atomic_read(&cpu_rq(i)->nr_iowait); + sum += nr_iowait_cpu(i); return sum; } -/* - * Consumers of these two interfaces, like for example the cpuidle menu - * governor, are using nonsensical data. Preferring shallow idle state selection - * for a CPU that has IO-wait which might not even end up running the task when - * it does become runnable. - */ - -unsigned long nr_iowait_cpu(int cpu) -{ - struct rq *this = cpu_rq(cpu); - return atomic_read(&this->nr_iowait); -} - -void get_iowait_load(unsigned long *nr_waiters, unsigned long *load) -{ - struct rq *rq = this_rq(); - *nr_waiters = atomic_read(&rq->nr_iowait); - *load = rq->load.weight; -} - #ifdef CONFIG_SMP /* @@ -5746,15 +5738,10 @@ int sched_cpu_activate(unsigned int cpu) #ifdef CONFIG_SCHED_SMT /* - * The sched_smt_present static key needs to be evaluated on every - * hotplug event because at boot time SMT might be disabled when - * the number of booted CPUs is limited. - * - * If then later a sibling gets hotplugged, then the key would stay - * off and SMT scheduling would never be functional. + * When going up, increment the number of cores with SMT present. */ - if (cpumask_weight(cpu_smt_mask(cpu)) > 1) - static_branch_enable_cpuslocked(&sched_smt_present); + if (cpumask_weight(cpu_smt_mask(cpu)) == 2) + static_branch_inc_cpuslocked(&sched_smt_present); #endif set_cpu_active(cpu, true); @@ -5798,6 +5785,14 @@ int sched_cpu_deactivate(unsigned int cpu) */ synchronize_rcu_mult(call_rcu, call_rcu_sched); +#ifdef CONFIG_SCHED_SMT + /* + * When going down, decrement the number of cores with SMT present. + */ + if (cpumask_weight(cpu_smt_mask(cpu)) == 2) + static_branch_dec_cpuslocked(&sched_smt_present); +#endif + if (!sched_smp_initialized) return 0; |