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| author | Mike Galbraith <efault@gmx.de> | 2010-03-11 17:17:15 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-03-11 18:32:51 +0100 |
| commit | 21406928afe43f1db6acab4931bb8c886f4d04ce (patch) | |
| tree | 623458f3c35ce4fbf18bcf4bba29c16c1c42c433 /kernel/sched_fair.c | |
| parent | a64692a3afd85fe048551ab89142fd5ca99a0dbd (diff) | |
| download | lwn-21406928afe43f1db6acab4931bb8c886f4d04ce.tar.gz lwn-21406928afe43f1db6acab4931bb8c886f4d04ce.zip | |
sched: Tweak sched_latency and min_granularity
Allow LAST_BUDDY to kick in sooner, improving cache utilization as soon as
a second buddy pair arrives on scene. The cost is latency starting to climb
sooner, the tbenefit for tbench 8 on my Q6600 box is ~2%. No detrimental
effects noted in normal idesktop usage.
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1268301285.6785.34.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/sched_fair.c')
| -rw-r--r-- | kernel/sched_fair.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index 69e582020ff8..d19df5bccfec 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -35,8 +35,8 @@ * (to see the precise effective timeslice length of your workload, * run vmstat and monitor the context-switches (cs) field) */ -unsigned int sysctl_sched_latency = 5000000ULL; -unsigned int normalized_sysctl_sched_latency = 5000000ULL; +unsigned int sysctl_sched_latency = 6000000ULL; +unsigned int normalized_sysctl_sched_latency = 6000000ULL; /* * The initial- and re-scaling of tunables is configurable @@ -52,15 +52,15 @@ enum sched_tunable_scaling sysctl_sched_tunable_scaling /* * Minimal preemption granularity for CPU-bound tasks: - * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds) + * (default: 2 msec * (1 + ilog(ncpus)), units: nanoseconds) */ -unsigned int sysctl_sched_min_granularity = 1000000ULL; -unsigned int normalized_sysctl_sched_min_granularity = 1000000ULL; +unsigned int sysctl_sched_min_granularity = 2000000ULL; +unsigned int normalized_sysctl_sched_min_granularity = 2000000ULL; /* * is kept at sysctl_sched_latency / sysctl_sched_min_granularity */ -static unsigned int sched_nr_latency = 5; +static unsigned int sched_nr_latency = 3; /* * After fork, child runs first. If set to 0 (default) then |