tree f7b1234ce9e8ad0bc5d5af949949251240ec6a2c
parent 1fc84aaae3bae9646dd4c7798b8c0ff934338909
author Peter Zijlstra <a.p.zijlstra@chello.nl> 1188060113 +0200
committer Ingo Molnar <mingo@elte.hu> 1188060113 +0200

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>