From 5f3edc1b1ead6d9bd45a85c551f44eff8fe76b9f Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 10 Sep 2009 13:42:00 +0200 Subject: sched: Hook sched_balance_self() into sched_class::select_task_rq() Rather ugly patch to fully place the sched_balance_self() code inside the fair class. Signed-off-by: Peter Zijlstra LKML-Reference: Signed-off-by: Ingo Molnar --- include/linux/sched.h | 3 ++- kernel/sched.c | 14 +++++++------- kernel/sched_fair.c | 7 ++++++- kernel/sched_idletask.c | 2 +- kernel/sched_rt.c | 5 ++++- 5 files changed, 20 insertions(+), 11 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index f3d74bd04d1..5d3c9900943 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -811,6 +811,7 @@ enum cpu_idle_type { #define SD_SERIALIZE 0x0400 /* Only a single load balancing instance */ #define SD_WAKE_IDLE_FAR 0x0800 /* Gain latency sacrificing cache hit */ #define SD_PREFER_SIBLING 0x1000 /* Prefer to place tasks in a sibling domain */ +#define SD_BALANCE_WAKE 0x2000 /* Balance on wakeup */ enum powersavings_balance_level { POWERSAVINGS_BALANCE_NONE = 0, /* No power saving load balance */ @@ -1032,7 +1033,7 @@ struct sched_class { void (*put_prev_task) (struct rq *rq, struct task_struct *p); #ifdef CONFIG_SMP - int (*select_task_rq)(struct task_struct *p, int sync); + int (*select_task_rq)(struct task_struct *p, int flag, int sync); unsigned long (*load_balance) (struct rq *this_rq, int this_cpu, struct rq *busiest, unsigned long max_load_move, diff --git a/kernel/sched.c b/kernel/sched.c index 60400a22401..32b7a81230c 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2350,7 +2350,7 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) if (unlikely(task_running(rq, p))) goto out_activate; - cpu = p->sched_class->select_task_rq(p, sync); + cpu = p->sched_class->select_task_rq(p, SD_BALANCE_WAKE, sync); if (cpu != orig_cpu) { set_task_cpu(p, cpu); task_rq_unlock(rq, &flags); @@ -2525,11 +2525,6 @@ void sched_fork(struct task_struct *p, int clone_flags) __sched_fork(p); -#ifdef CONFIG_SMP - cpu = sched_balance_self(cpu, SD_BALANCE_FORK); -#endif - set_task_cpu(p, cpu); - /* * Make sure we do not leak PI boosting priority to the child. */ @@ -2560,6 +2555,11 @@ void sched_fork(struct task_struct *p, int clone_flags) if (!rt_prio(p->prio)) p->sched_class = &fair_sched_class; +#ifdef CONFIG_SMP + cpu = p->sched_class->select_task_rq(p, SD_BALANCE_FORK, 0); +#endif + set_task_cpu(p, cpu); + #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) if (likely(sched_info_on())) memset(&p->sched_info, 0, sizeof(p->sched_info)); @@ -3114,7 +3114,7 @@ out: void sched_exec(void) { int new_cpu, this_cpu = get_cpu(); - new_cpu = sched_balance_self(this_cpu, SD_BALANCE_EXEC); + new_cpu = current->sched_class->select_task_rq(current, SD_BALANCE_EXEC, 0); put_cpu(); if (new_cpu != this_cpu) sched_migrate_task(current, new_cpu); diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index a82d71d3afe..f2eb5b93471 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1300,7 +1300,9 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq, return 0; } -static int select_task_rq_fair(struct task_struct *p, int sync) +static int sched_balance_self(int cpu, int flag); + +static int select_task_rq_fair(struct task_struct *p, int flag, int sync) { struct sched_domain *sd, *this_sd = NULL; int prev_cpu, this_cpu, new_cpu; @@ -1314,6 +1316,9 @@ static int select_task_rq_fair(struct task_struct *p, int sync) this_rq = cpu_rq(this_cpu); new_cpu = prev_cpu; + if (flag != SD_BALANCE_WAKE) + return sched_balance_self(this_cpu, flag); + /* * 'this_sd' is the first domain that both * this_cpu and prev_cpu are present in: diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c index 499672c10cb..99b2f033760 100644 --- a/kernel/sched_idletask.c +++ b/kernel/sched_idletask.c @@ -6,7 +6,7 @@ */ #ifdef CONFIG_SMP -static int select_task_rq_idle(struct task_struct *p, int sync) +static int select_task_rq_idle(struct task_struct *p, int flag, int sync) { return task_cpu(p); /* IDLE tasks as never migrated */ } diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 2eb4bd6a526..438380810ac 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -938,10 +938,13 @@ static void yield_task_rt(struct rq *rq) #ifdef CONFIG_SMP static int find_lowest_rq(struct task_struct *task); -static int select_task_rq_rt(struct task_struct *p, int sync) +static int select_task_rq_rt(struct task_struct *p, int flag, int sync) { struct rq *rq = task_rq(p); + if (flag != SD_BALANCE_WAKE) + return smp_processor_id(); + /* * If the current task is an RT task, then * try to see if we can wake this RT task up on another -- cgit v1.2.3