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sched: Hook sched_balance_self() into sched_class::select_task_rq()

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Rather ugly patch to fully place the sched_balance_self() code
inside the fair class.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2009-09-10 13:42:00 +02:00 • committed by Ingo Molnar
commit 5f3edc1b1e
5 changed files with 20 additions and 11 deletions
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3
include/linux/sched.h
View file

@ -811,6 +811,7 @@ enum cpu_idle_type {
#define SD_SERIALIZE 0x0400 /* Only a single load balancing instance */ #define SD_SERIALIZE 0x0400 /* Only a single load balancing instance */
#define SD_WAKE_IDLE_FAR 0x0800 /* Gain latency sacrificing cache hit */ #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_PREFER_SIBLING 0x1000 /* Prefer to place tasks in a sibling domain */
#define SD_BALANCE_WAKE 0x2000 /* Balance on wakeup */
enum powersavings_balance_level { enum powersavings_balance_level {
POWERSAVINGS_BALANCE_NONE = 0, /* No power saving load balance */ 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); void (*put_prev_task) (struct rq *rq, struct task_struct *p);
#ifdef CONFIG_SMP #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, unsigned long (*load_balance) (struct rq *this_rq, int this_cpu,
struct rq *busiest, unsigned long max_load_move, struct rq *busiest, unsigned long max_load_move,

14
kernel/sched.c
View file

@ -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))) if (unlikely(task_running(rq, p)))
goto out_activate; 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) { if (cpu != orig_cpu) {
set_task_cpu(p, cpu); set_task_cpu(p, cpu);
task_rq_unlock(rq, &flags); task_rq_unlock(rq, &flags);
@ -2525,11 +2525,6 @@ void sched_fork(struct task_struct *p, int clone_flags)
__sched_fork(p); __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. * 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)) if (!rt_prio(p->prio))
p->sched_class = &fair_sched_class; 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 defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
if (likely(sched_info_on())) if (likely(sched_info_on()))
memset(&p->sched_info, 0, sizeof(p->sched_info)); memset(&p->sched_info, 0, sizeof(p->sched_info));
@ -3114,7 +3114,7 @@ out:
void sched_exec(void) void sched_exec(void)
{ {
int new_cpu, this_cpu = get_cpu(); 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(); put_cpu();
if (new_cpu != this_cpu) if (new_cpu != this_cpu)
sched_migrate_task(current, new_cpu); sched_migrate_task(current, new_cpu);

7
kernel/sched_fair.c
View file

@ -1300,7 +1300,9 @@ wake_affine(struct sched_domain *this_sd, struct rq *this_rq,
return 0; 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; struct sched_domain *sd, *this_sd = NULL;
int prev_cpu, this_cpu, new_cpu; 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); this_rq = cpu_rq(this_cpu);
new_cpu = prev_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_sd' is the first domain that both
* this_cpu and prev_cpu are present in: * this_cpu and prev_cpu are present in:

2
kernel/sched_idletask.c
View file

@ -6,7 +6,7 @@
*/ */
#ifdef CONFIG_SMP #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 */ return task_cpu(p); /* IDLE tasks as never migrated */
} }

5
kernel/sched_rt.c
View file

@ -938,10 +938,13 @@ static void yield_task_rt(struct rq *rq)
#ifdef CONFIG_SMP #ifdef CONFIG_SMP
static int find_lowest_rq(struct task_struct *task); 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); struct rq *rq = task_rq(p);
if (flag != SD_BALANCE_WAKE)
return smp_processor_id();
/* /*
* If the current task is an RT task, then * If the current task is an RT task, then
* try to see if we can wake this RT task up on another * try to see if we can wake this RT task up on another