From 6d63f38bf2832a353cab15d9070fe8171b03bd22 Mon Sep 17 00:00:00 2001 From: Pavankumar Kondeti Date: Sat, 7 Jan 2017 14:59:26 +0530 Subject: sched: kill sync_cpu maintenance We assume boot CPU as a sync CPU and initialize it's window_start to sched_ktime_clock(). As windows are synchronized across all CPUs, the secondary CPUs' window_start are initialized from the sync_cpu's window_start. A CPU's window_start is never reset, so this synchronization happens only once for a given CPU. Given this fact, there is no need to reassigning the sync_cpu role to another CPU when the boot CPU is going offline. Remove this unnecessary maintenance of sync_cpu and use any online CPU's window_start as reference. Change-Id: I169a8e80573c6dbcb1edeab0659c07c17102f4c9 Signed-off-by: Pavankumar Kondeti --- kernel/sched/hmp.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) (limited to 'kernel/sched/hmp.c') diff --git a/kernel/sched/hmp.c b/kernel/sched/hmp.c index 443f16732414..433d19663496 100644 --- a/kernel/sched/hmp.c +++ b/kernel/sched/hmp.c @@ -788,8 +788,6 @@ __read_mostly unsigned int sched_ravg_window = MIN_SCHED_RAVG_WINDOW; /* Temporarily disable window-stats activity on all cpus */ unsigned int __read_mostly sched_disable_window_stats; -static unsigned int sync_cpu; - struct related_thread_group *related_thread_groups[MAX_NUM_CGROUP_COLOC_ID]; static LIST_HEAD(active_related_thread_groups); static DEFINE_RWLOCK(related_thread_group_lock); @@ -3015,18 +3013,20 @@ void mark_task_starting(struct task_struct *p) void set_window_start(struct rq *rq) { - int cpu = cpu_of(rq); - struct rq *sync_rq = cpu_rq(sync_cpu); + static int sync_cpu_available; if (rq->window_start || !sched_enable_hmp) return; - if (cpu == sync_cpu) { + if (!sync_cpu_available) { rq->window_start = sched_ktime_clock(); + sync_cpu_available = 1; } else { + struct rq *sync_rq = cpu_rq(cpumask_any(cpu_online_mask)); + raw_spin_unlock(&rq->lock); double_rq_lock(rq, sync_rq); - rq->window_start = cpu_rq(sync_cpu)->window_start; + rq->window_start = sync_rq->window_start; rq->curr_runnable_sum = rq->prev_runnable_sum = 0; rq->nt_curr_runnable_sum = rq->nt_prev_runnable_sum = 0; raw_spin_unlock(&sync_rq->lock); @@ -3035,12 +3035,6 @@ void set_window_start(struct rq *rq) rq->curr->ravg.mark_start = rq->window_start; } -void migrate_sync_cpu(int cpu, int new_cpu) -{ - if (cpu == sync_cpu) - sync_cpu = new_cpu; -} - static void reset_all_task_stats(void) { struct task_struct *g, *p; -- cgit v1.2.3