From e51fd5e22e12b39f49b1bb60b37b300b17378a43 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 31 May 2010 12:37:30 +0200 Subject: sched: Fix wake_affine() vs RT tasks Mike reports that since e9e9250b (sched: Scale down cpu_power due to RT tasks), wake_affine() goes funny on RT tasks due to them still having a !0 weight and wake_affine() still subtracts that from the rq weight. Since nobody should be using se->weight for RT tasks, set the value to zero. Also, since we now use ->cpu_power to normalize rq weights to account for RT cpu usage, add that factor into the imbalance computation. Reported-by: Mike Galbraith Tested-by: Mike Galbraith Signed-off-by: Peter Zijlstra LKML-Reference: <1275316109.27810.22969.camel@twins> Signed-off-by: Ingo Molnar --- kernel/sched.c | 24 ++++++------------------ 1 file changed, 6 insertions(+), 18 deletions(-) (limited to 'kernel/sched.c') diff --git a/kernel/sched.c b/kernel/sched.c index d48408142503..f8b8996228dd 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -544,6 +544,8 @@ struct rq { struct root_domain *rd; struct sched_domain *sd; + unsigned long cpu_power; + unsigned char idle_at_tick; /* For active balancing */ int post_schedule; @@ -1499,24 +1501,9 @@ static unsigned long target_load(int cpu, int type) return max(rq->cpu_load[type-1], total); } -static struct sched_group *group_of(int cpu) -{ - struct sched_domain *sd = rcu_dereference_sched(cpu_rq(cpu)->sd); - - if (!sd) - return NULL; - - return sd->groups; -} - static unsigned long power_of(int cpu) { - struct sched_group *group = group_of(cpu); - - if (!group) - return SCHED_LOAD_SCALE; - - return group->cpu_power; + return cpu_rq(cpu)->cpu_power; } static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); @@ -1854,8 +1841,8 @@ static void dec_nr_running(struct rq *rq) static void set_load_weight(struct task_struct *p) { if (task_has_rt_policy(p)) { - p->se.load.weight = prio_to_weight[0] * 2; - p->se.load.inv_weight = prio_to_wmult[0] >> 1; + p->se.load.weight = 0; + p->se.load.inv_weight = WMULT_CONST; return; } @@ -7605,6 +7592,7 @@ void __init sched_init(void) #ifdef CONFIG_SMP rq->sd = NULL; rq->rd = NULL; + rq->cpu_power = SCHED_LOAD_SCALE; rq->post_schedule = 0; rq->active_balance = 0; rq->next_balance = jiffies; -- cgit v1.2.2