[PATCH V5 1/8] sched: shortcut to remove load_idx

From: Alex Shi
Date: Tue Apr 15 2014 - 22:45:16 EST


Shortcut to remove rq->cpu_load[load_idx] effect in scheduler.
In five load idx, only busy_idx, idle_idx are not zero.
Newidle_idx, wake_idx and fork_idx are all zero in all archs.

So, change the idx to zero here can fully remove load_idx effect.

Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxx>
---
kernel/sched/fair.c | 30 +-----------------------------
1 file changed, 1 insertion(+), 29 deletions(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 4f14a65..ddff32a 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5507,34 +5507,6 @@ static inline void init_sd_lb_stats(struct sd_lb_stats *sds)
};
}

-/**
- * get_sd_load_idx - Obtain the load index for a given sched domain.
- * @sd: The sched_domain whose load_idx is to be obtained.
- * @idle: The idle status of the CPU for whose sd load_idx is obtained.
- *
- * Return: The load index.
- */
-static inline int get_sd_load_idx(struct sched_domain *sd,
- enum cpu_idle_type idle)
-{
- int load_idx;
-
- switch (idle) {
- case CPU_NOT_IDLE:
- load_idx = sd->busy_idx;
- break;
-
- case CPU_NEWLY_IDLE:
- load_idx = sd->newidle_idx;
- break;
- default:
- load_idx = sd->idle_idx;
- break;
- }
-
- return load_idx;
-}
-
static unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu)
{
return SCHED_POWER_SCALE;
@@ -5920,7 +5892,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd
if (child && child->flags & SD_PREFER_SIBLING)
prefer_sibling = 1;

- load_idx = get_sd_load_idx(env->sd, env->idle);
+ load_idx = 0;

do {
struct sg_lb_stats *sgs = &tmp_sgs;
--
1.8.3.2

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