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authorChristoph Lameter <clameter@sgi.com>2006-12-10 05:20:22 -0500
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-10 12:55:42 -0500
commit7835b98bc6de2ca10afa45572d272304b000b048 (patch)
tree6c029f271821b00d18f5f318526b80511b409838 /kernel
parentfe2eea3fafb3df2f5b8a55a48bcbb0d23b3b5618 (diff)
[PATCH] sched: extract load calculation from rebalance_tick
A load calculation is always done in rebalance_tick() in addition to the real load balancing activities that only take place when certain jiffie counts have been reached. Move that processing into a separate function and call it directly from scheduler_tick(). Also extract the time slice handling from scheduler_tick and put it into a separate function. Then we can clean up scheduler_tick significantly. It will no longer have any gotos. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Peter Williams <pwil3058@bigpond.net.au> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Christoph Lameter <clameter@sgi.com> Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com> Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sched.c96
1 files changed, 54 insertions, 42 deletions
diff --git a/kernel/sched.c b/kernel/sched.c
index d327511d268e..3c1b74aa1b07 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2833,20 +2833,9 @@ static void active_load_balance(struct rq *busiest_rq, int busiest_cpu)
2833 spin_unlock(&target_rq->lock); 2833 spin_unlock(&target_rq->lock);
2834} 2834}
2835 2835
2836/* 2836static void update_load(struct rq *this_rq)
2837 * rebalance_tick will get called every timer tick, on every CPU.
2838 *
2839 * It checks each scheduling domain to see if it is due to be balanced,
2840 * and initiates a balancing operation if so.
2841 *
2842 * Balancing parameters are set up in arch_init_sched_domains.
2843 */
2844
2845static void
2846rebalance_tick(int this_cpu, struct rq *this_rq, enum idle_type idle)
2847{ 2837{
2848 unsigned long this_load, interval; 2838 unsigned long this_load;
2849 struct sched_domain *sd;
2850 int i, scale; 2839 int i, scale;
2851 2840
2852 this_load = this_rq->raw_weighted_load; 2841 this_load = this_rq->raw_weighted_load;
@@ -2866,6 +2855,22 @@ rebalance_tick(int this_cpu, struct rq *this_rq, enum idle_type idle)
2866 new_load += scale-1; 2855 new_load += scale-1;
2867 this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) / scale; 2856 this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) / scale;
2868 } 2857 }
2858}
2859
2860/*
2861 * rebalance_tick will get called every timer tick, on every CPU.
2862 *
2863 * It checks each scheduling domain to see if it is due to be balanced,
2864 * and initiates a balancing operation if so.
2865 *
2866 * Balancing parameters are set up in arch_init_sched_domains.
2867 */
2868
2869static void
2870rebalance_tick(int this_cpu, struct rq *this_rq, enum idle_type idle)
2871{
2872 unsigned long interval;
2873 struct sched_domain *sd;
2869 2874
2870 for_each_domain(this_cpu, sd) { 2875 for_each_domain(this_cpu, sd) {
2871 if (!(sd->flags & SD_LOAD_BALANCE)) 2876 if (!(sd->flags & SD_LOAD_BALANCE))
@@ -2897,12 +2902,15 @@ rebalance_tick(int this_cpu, struct rq *this_rq, enum idle_type idle)
2897/* 2902/*
2898 * on UP we do not need to balance between CPUs: 2903 * on UP we do not need to balance between CPUs:
2899 */ 2904 */
2900static inline void rebalance_tick(int cpu, struct rq *rq, enum idle_type idle) 2905static inline void rebalance_tick(int cpu, struct rq *rq)
2901{ 2906{
2902} 2907}
2903static inline void idle_balance(int cpu, struct rq *rq) 2908static inline void idle_balance(int cpu, struct rq *rq)
2904{ 2909{
2905} 2910}
2911static inline void update_load(struct rq *this_rq)
2912{
2913}
2906#endif 2914#endif
2907 2915
2908static inline int wake_priority_sleeper(struct rq *rq) 2916static inline int wake_priority_sleeper(struct rq *rq)
@@ -3052,35 +3060,12 @@ void account_steal_time(struct task_struct *p, cputime_t steal)
3052 cpustat->steal = cputime64_add(cpustat->steal, tmp); 3060 cpustat->steal = cputime64_add(cpustat->steal, tmp);
3053} 3061}
3054 3062
3055/* 3063static void task_running_tick(struct rq *rq, struct task_struct *p)
3056 * This function gets called by the timer code, with HZ frequency.
3057 * We call it with interrupts disabled.
3058 *
3059 * It also gets called by the fork code, when changing the parent's
3060 * timeslices.
3061 */
3062void scheduler_tick(void)
3063{ 3064{
3064 unsigned long long now = sched_clock();
3065 struct task_struct *p = current;
3066 int cpu = smp_processor_id();
3067 struct rq *rq = cpu_rq(cpu);
3068
3069 update_cpu_clock(p, rq, now);
3070
3071 rq->timestamp_last_tick = now;
3072
3073 if (p == rq->idle) {
3074 if (wake_priority_sleeper(rq))
3075 goto out;
3076 rebalance_tick(cpu, rq, SCHED_IDLE);
3077 return;
3078 }
3079
3080 /* Task might have expired already, but not scheduled off yet */
3081 if (p->array != rq->active) { 3065 if (p->array != rq->active) {
3066 /* Task has expired but was not scheduled yet */
3082 set_tsk_need_resched(p); 3067 set_tsk_need_resched(p);
3083 goto out; 3068 return;
3084 } 3069 }
3085 spin_lock(&rq->lock); 3070 spin_lock(&rq->lock);
3086 /* 3071 /*
@@ -3148,8 +3133,35 @@ void scheduler_tick(void)
3148 } 3133 }
3149out_unlock: 3134out_unlock:
3150 spin_unlock(&rq->lock); 3135 spin_unlock(&rq->lock);
3151out: 3136}
3152 rebalance_tick(cpu, rq, NOT_IDLE); 3137
3138/*
3139 * This function gets called by the timer code, with HZ frequency.
3140 * We call it with interrupts disabled.
3141 *
3142 * It also gets called by the fork code, when changing the parent's
3143 * timeslices.
3144 */
3145void scheduler_tick(void)
3146{
3147 unsigned long long now = sched_clock();
3148 struct task_struct *p = current;
3149 int cpu = smp_processor_id();
3150 struct rq *rq = cpu_rq(cpu);
3151 enum idle_type idle = NOT_IDLE;
3152
3153 update_cpu_clock(p, rq, now);
3154
3155 rq->timestamp_last_tick = now;
3156
3157 if (p == rq->idle) {
3158 /* Task on the idle queue */
3159 if (!wake_priority_sleeper(rq))
3160 idle = SCHED_IDLE;
3161 } else
3162 task_running_tick(rq, p);
3163 update_load(rq);
3164 rebalance_tick(cpu, rq, idle);
3153} 3165}
3154 3166
3155#ifdef CONFIG_SCHED_SMT 3167#ifdef CONFIG_SCHED_SMT