提交 098fb9db 编写于 作者: I Ingo Molnar

sched: clean up wakeup balancing, move wake_affine()

split out the affine-wakeup bits.

No code changed:

kernel/sched.o:

   text	   data	    bss	    dec	    hex	filename
  42521	   2858	    232	  45611	   b22b	sched.o.before
  42521	   2858	    232	  45611	   b22b	sched.o.after

md5:
   9d76738f1272aa82f0b7affd2f51df6b  sched.o.before.asm
   09b31c44e9aff8666f72773dc433e2df  sched.o.after.asm

(the md5's changed because stack slots changed and some registers
get scheduled by gcc in a different order - but otherwise the before
and after assembly is instruction for instruction equivalent.)
Signed-off-by: NIngo Molnar <mingo@elte.hu>
上级 f920bb6f
......@@ -980,12 +980,59 @@ static inline int wake_idle(int cpu, struct task_struct *p)
#endif
#ifdef CONFIG_SMP
static int
wake_affine(struct rq *rq, struct sched_domain *this_sd, struct task_struct *p,
int cpu, int this_cpu, int sync, int idx,
unsigned long load, unsigned long this_load,
unsigned int imbalance)
{
unsigned long tl = this_load;
unsigned long tl_per_task;
if (!(this_sd->flags & SD_WAKE_AFFINE))
return 0;
/*
* Attract cache-cold tasks on sync wakeups:
*/
if (sync && !task_hot(p, rq->clock, this_sd))
return 1;
schedstat_inc(p, se.nr_wakeups_affine_attempts);
tl_per_task = cpu_avg_load_per_task(this_cpu);
/*
* If sync wakeup then subtract the (maximum possible)
* effect of the currently running task from the load
* of the current CPU:
*/
if (sync)
tl -= current->se.load.weight;
if ((tl <= load && tl + target_load(cpu, idx) <= tl_per_task) ||
100*(tl + p->se.load.weight) <= imbalance*load) {
/*
* This domain has SD_WAKE_AFFINE and
* p is cache cold in this domain, and
* there is no bad imbalance.
*/
schedstat_inc(this_sd, ttwu_move_affine);
schedstat_inc(p, se.nr_wakeups_affine);
return 1;
}
return 0;
}
static int select_task_rq_fair(struct task_struct *p, int sync)
{
int cpu, this_cpu;
struct rq *rq;
struct sched_domain *sd, *this_sd = NULL;
int new_cpu;
unsigned long load, this_load;
int cpu, this_cpu, new_cpu;
unsigned int imbalance;
struct rq *rq;
int idx;
cpu = task_cpu(p);
rq = task_rq(p);
......@@ -1008,66 +1055,35 @@ static int select_task_rq_fair(struct task_struct *p, int sync)
/*
* Check for affine wakeup and passive balancing possibilities.
*/
if (this_sd) {
int idx = this_sd->wake_idx;
unsigned int imbalance;
unsigned long load, this_load;
imbalance = 100 + (this_sd->imbalance_pct - 100) / 2;
load = source_load(cpu, idx);
this_load = target_load(this_cpu, idx);
new_cpu = this_cpu; /* Wake to this CPU if we can */
if (this_sd->flags & SD_WAKE_AFFINE) {
unsigned long tl = this_load;
unsigned long tl_per_task;
/*
* Attract cache-cold tasks on sync wakeups:
*/
if (sync && !task_hot(p, rq->clock, this_sd))
goto out_set_cpu;
schedstat_inc(p, se.nr_wakeups_affine_attempts);
tl_per_task = cpu_avg_load_per_task(this_cpu);
/*
* If sync wakeup then subtract the (maximum possible)
* effect of the currently running task from the load
* of the current CPU:
*/
if (sync)
tl -= current->se.load.weight;
if ((tl <= load &&
tl + target_load(cpu, idx) <= tl_per_task) ||
100*(tl + p->se.load.weight) <= imbalance*load) {
/*
* This domain has SD_WAKE_AFFINE and
* p is cache cold in this domain, and
* there is no bad imbalance.
*/
schedstat_inc(this_sd, ttwu_move_affine);
schedstat_inc(p, se.nr_wakeups_affine);
goto out_set_cpu;
}
}
if (!this_sd)
goto out_keep_cpu;
/*
* Start passive balancing when half the imbalance_pct
* limit is reached.
*/
if (this_sd->flags & SD_WAKE_BALANCE) {
if (imbalance*this_load <= 100*load) {
schedstat_inc(this_sd, ttwu_move_balance);
schedstat_inc(p, se.nr_wakeups_passive);
goto out_set_cpu;
}
idx = this_sd->wake_idx;
imbalance = 100 + (this_sd->imbalance_pct - 100) / 2;
load = source_load(cpu, idx);
this_load = target_load(this_cpu, idx);
new_cpu = this_cpu; /* Wake to this CPU if we can */
if (wake_affine(rq, this_sd, p, cpu, this_cpu, sync, idx,
load, this_load, imbalance))
goto out_set_cpu;
/*
* Start passive balancing when half the imbalance_pct
* limit is reached.
*/
if (this_sd->flags & SD_WAKE_BALANCE) {
if (imbalance*this_load <= 100*load) {
schedstat_inc(this_sd, ttwu_move_balance);
schedstat_inc(p, se.nr_wakeups_passive);
goto out_set_cpu;
}
}
out_keep_cpu:
new_cpu = cpu; /* Could not wake to this_cpu. Wake to cpu instead */
out_set_cpu:
return wake_idle(new_cpu, p);
......
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