diff options
| -rw-r--r-- | block/blk-softirq.c | 16 | ||||
| -rw-r--r-- | block/blk.h | 16 | ||||
| -rw-r--r-- | include/linux/sched.h | 8 | ||||
| -rw-r--r-- | kernel/sched/core.c | 6 |
4 files changed, 19 insertions, 27 deletions
diff --git a/block/blk-softirq.c b/block/blk-softirq.c index 1366a89d8e6..467c8de8864 100644 --- a/block/blk-softirq.c +++ b/block/blk-softirq.c @@ -8,6 +8,7 @@ #include <linux/blkdev.h> #include <linux/interrupt.h> #include <linux/cpu.h> +#include <linux/sched.h> #include "blk.h" @@ -103,9 +104,10 @@ static struct notifier_block __cpuinitdata blk_cpu_notifier = { void __blk_complete_request(struct request *req) { - int ccpu, cpu, group_cpu = NR_CPUS; + int ccpu, cpu; struct request_queue *q = req->q; unsigned long flags; + bool shared = false; BUG_ON(!q->softirq_done_fn); @@ -117,22 +119,20 @@ void __blk_complete_request(struct request *req) */ if (req->cpu != -1) { ccpu = req->cpu; - if (!test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags)) { - ccpu = blk_cpu_to_group(ccpu); - group_cpu = blk_cpu_to_group(cpu); - } + if (!test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags)) + shared = cpus_share_cache(cpu, ccpu); } else ccpu = cpu; /* - * If current CPU and requested CPU are in the same group, running - * softirq in current CPU. One might concern this is just like + * If current CPU and requested CPU share a cache, run the softirq on + * the current CPU. One might concern this is just like * QUEUE_FLAG_SAME_FORCE, but actually not. blk_complete_request() is * running in interrupt handler, and currently I/O controller doesn't * support multiple interrupts, so current CPU is unique actually. This * avoids IPI sending from current CPU to the first CPU of a group. */ - if (ccpu == cpu || ccpu == group_cpu) { + if (ccpu == cpu || shared) { struct list_head *list; do_local: list = &__get_cpu_var(blk_cpu_done); diff --git a/block/blk.h b/block/blk.h index 7efd772336d..df5b59acbdf 100644 --- a/block/blk.h +++ b/block/blk.h @@ -164,22 +164,6 @@ static inline int queue_congestion_off_threshold(struct request_queue *q) return q->nr_congestion_off; } -static inline int blk_cpu_to_group(int cpu) -{ - int group = NR_CPUS; -#ifdef CONFIG_SCHED_MC - const struct cpumask *mask = cpu_coregroup_mask(cpu); - group = cpumask_first(mask); -#elif defined(CONFIG_SCHED_SMT) - group = cpumask_first(topology_thread_cpumask(cpu)); -#else - return cpu; -#endif - if (likely(group < NR_CPUS)) - return group; - return cpu; -} - /* * Contribute to IO statistics IFF: * diff --git a/include/linux/sched.h b/include/linux/sched.h index 513f5245987..0e195956883 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1052,6 +1052,8 @@ static inline int test_sd_parent(struct sched_domain *sd, int flag) unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu); unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu); +bool cpus_share_cache(int this_cpu, int that_cpu); + #else /* CONFIG_SMP */ struct sched_domain_attr; @@ -1061,6 +1063,12 @@ partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], struct sched_domain_attr *dattr_new) { } + +static inline bool cpus_share_cache(int this_cpu, int that_cpu) +{ + return true; +} + #endif /* !CONFIG_SMP */ diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 5255c9d2e05..d7c43227311 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1507,7 +1507,7 @@ static int ttwu_activate_remote(struct task_struct *p, int wake_flags) } #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ -static inline int ttwu_share_cache(int this_cpu, int that_cpu) +bool cpus_share_cache(int this_cpu, int that_cpu) { return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu); } @@ -1518,7 +1518,7 @@ static void ttwu_queue(struct task_struct *p, int cpu) struct rq *rq = cpu_rq(cpu); #if defined(CONFIG_SMP) - if (sched_feat(TTWU_QUEUE) && !ttwu_share_cache(smp_processor_id(), cpu)) { + if (sched_feat(TTWU_QUEUE) && !cpus_share_cache(smp_processor_id(), cpu)) { sched_clock_cpu(cpu); /* sync clocks x-cpu */ ttwu_queue_remote(p, cpu); return; @@ -5754,7 +5754,7 @@ static void destroy_sched_domains(struct sched_domain *sd, int cpu) * * Also keep a unique ID per domain (we use the first cpu number in * the cpumask of the domain), this allows us to quickly tell if - * two cpus are in the same cache domain, see ttwu_share_cache(). + * two cpus are in the same cache domain, see cpus_share_cache(). */ DEFINE_PER_CPU(struct sched_domain *, sd_llc); DEFINE_PER_CPU(int, sd_llc_id); |