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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2007-08-25 18:41:53 +0200
committerIngo Molnar <mingo@elte.hu>2007-08-25 18:41:53 +0200
commit218050855ece4e923106ab614ac65afa0f618df3 (patch)
treef7b1234ce9e8ad0bc5d5af949949251240ec6a2c /include/linux/sched.h
parent1fc84aaae3bae9646dd4c7798b8c0ff934338909 (diff)
sched: adaptive scheduler granularity
Instead of specifying the preemption granularity, specify the wanted latency. By fixing the granlarity to a constany the wakeup latency it a function of the number of running tasks on the rq. Invert this relation. sysctl_sched_granularity becomes a minimum for the dynamic granularity computed from the new sysctl_sched_latency. Then use this latency to do more intelligent granularity decisions: if there are fewer tasks running then we can schedule coarser. This helps performance while still always keeping the latency target. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/linux/sched.h')
-rw-r--r--include/linux/sched.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index ba78807eab91..322764e04052 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1399,6 +1399,7 @@ static inline void idle_task_exit(void) {}
extern void sched_idle_next(void);
+extern unsigned int sysctl_sched_latency;
extern unsigned int sysctl_sched_granularity;
extern unsigned int sysctl_sched_wakeup_granularity;
extern unsigned int sysctl_sched_batch_wakeup_granularity;