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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2008-06-27 13:41:26 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-06-27 14:31:39 +0200 |
| commit | a8a51d5e59561aa5b4d66e19eca819b537783e8f (patch) | |
| tree | b400bc77244a742e737bb9deb94a6911a769e082 /kernel | |
| parent | 039a1c41b3a489e34593ea1e1687f6fdad6b13ab (diff) | |
| download | linux-a8a51d5e59561aa5b4d66e19eca819b537783e8f.tar.gz linux-a8a51d5e59561aa5b4d66e19eca819b537783e8f.tar.bz2 linux-a8a51d5e59561aa5b4d66e19eca819b537783e8f.zip | |
sched: persistent average load per task
Remove the fall-back to SCHED_LOAD_SCALE by remembering the previous value of
cpu_avg_load_per_task() - this is useful because of the hierarchical group
model in which task weight can be much smaller.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Cc: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched.c | 25 |
1 files changed, 12 insertions, 13 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index 39d5495540d2..6a6b0139eb32 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -554,6 +554,8 @@ struct rq { int cpu; int online; + unsigned long avg_load_per_task; + struct task_struct *migration_thread; struct list_head migration_queue; #endif @@ -1427,9 +1429,18 @@ static inline void dec_cpu_load(struct rq *rq, unsigned long load) #ifdef CONFIG_SMP static unsigned long source_load(int cpu, int type); static unsigned long target_load(int cpu, int type); -static unsigned long cpu_avg_load_per_task(int cpu); static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); +static unsigned long cpu_avg_load_per_task(int cpu) +{ + struct rq *rq = cpu_rq(cpu); + + if (rq->nr_running) + rq->avg_load_per_task = rq->load.weight / rq->nr_running; + + return rq->avg_load_per_task; +} + #ifdef CONFIG_FAIR_GROUP_SCHED typedef void (*tg_visitor)(struct task_group *, int, struct sched_domain *); @@ -2011,18 +2022,6 @@ static unsigned long target_load(int cpu, int type) } /* - * Return the average load per task on the cpu's run queue - */ -static unsigned long cpu_avg_load_per_task(int cpu) -{ - struct rq *rq = cpu_rq(cpu); - unsigned long total = weighted_cpuload(cpu); - unsigned long n = rq->nr_running; - - return n ? total / n : SCHED_LOAD_SCALE; -} - -/* * find_idlest_group finds and returns the least busy CPU group within the * domain. */ |