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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2008-01-25 21:08:29 +0100
committerIngo Molnar <mingo@elte.hu>2008-01-25 21:08:29 +0100
commit8f4d37ec073c17e2d4aa8851df5837d798606d6f (patch)
treea9ac9063eca53e4d0110e8086f55241ea70ba993 /kernel/Kconfig.hz
parent02b67cc3ba36bdba351d6c3a00593f4ec550d9d3 (diff)
downloadlinux-sh-8f4d37ec073c17e2d4aa8851df5837d798606d6f.tar.gz
sched: high-res preemption tick
Use HR-timers (when available) to deliver an accurate preemption tick. The regular scheduler tick that runs at 1/HZ can be too coarse when nice level are used. The fairness system will still keep the cpu utilisation 'fair' by then delaying the task that got an excessive amount of CPU time but try to minimize this by delivering preemption points spot-on. The average frequency of this extra interrupt is sched_latency / nr_latency. Which need not be higher than 1/HZ, its just that the distribution within the sched_latency period is important. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/Kconfig.hz')
-rw-r--r--kernel/Kconfig.hz2
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/Kconfig.hz b/kernel/Kconfig.hz
index 4af15802ccd4..526128a2e622 100644
--- a/kernel/Kconfig.hz
+++ b/kernel/Kconfig.hz
@@ -54,3 +54,5 @@ config HZ
default 300 if HZ_300
default 1000 if HZ_1000
+config SCHED_HRTICK
+ def_bool HIGH_RES_TIMERS && X86