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| author | Zou Nan hai <nanhai.zou@intel.com> | 2007-11-26 21:21:49 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2007-11-26 21:21:49 +0100 |
| commit | 722aab0c3bbd7648d66790515c14d95d10a15bf3 (patch) | |
| tree | f1a2f2c8cbcdcffac8bc6f05d17a8711f611aa96 | |
| parent | 58e1010da3c15e7bdf426b0a3d4b13dba1b7d055 (diff) | |
| download | lwn-722aab0c3bbd7648d66790515c14d95d10a15bf3.tar.gz lwn-722aab0c3bbd7648d66790515c14d95d10a15bf3.zip | |
sched: fix minimum granularity tunings
increase the default minimum granularity some more - this gives us
more performance in aim7 benchmarks.
also correct some comments: we scale with ilog(ncpus) + 1.
Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -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 ee00da284b12..2f16e15c022c 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -22,7 +22,7 @@ /* * Targeted preemption latency for CPU-bound tasks: - * (default: 20ms * ilog(ncpus), units: nanoseconds) + * (default: 20ms * (1 + ilog(ncpus)), units: nanoseconds) * * NOTE: this latency value is not the same as the concept of * 'timeslice length' - timeslices in CFS are of variable length @@ -36,14 +36,14 @@ unsigned int sysctl_sched_latency = 20000000ULL; /* * Minimal preemption granularity for CPU-bound tasks: - * (default: 1 msec * ilog(ncpus), units: nanoseconds) + * (default: 4 msec * (1 + ilog(ncpus)), units: nanoseconds) */ -unsigned int sysctl_sched_min_granularity = 1000000ULL; +unsigned int sysctl_sched_min_granularity = 4000000ULL; /* * is kept at sysctl_sched_latency / sysctl_sched_min_granularity */ -static unsigned int sched_nr_latency = 20; +static unsigned int sched_nr_latency = 5; /* * After fork, child runs first. (default) If set to 0 then @@ -61,7 +61,7 @@ unsigned int __read_mostly sysctl_sched_compat_yield; /* * SCHED_BATCH wake-up granularity. - * (default: 10 msec * ilog(ncpus), units: nanoseconds) + * (default: 10 msec * (1 + ilog(ncpus)), units: nanoseconds) * * This option delays the preemption effects of decoupled workloads * and reduces their over-scheduling. Synchronous workloads will still @@ -71,7 +71,7 @@ unsigned int sysctl_sched_batch_wakeup_granularity = 10000000UL; /* * SCHED_OTHER wake-up granularity. - * (default: 10 msec * ilog(ncpus), units: nanoseconds) + * (default: 10 msec * (1 + ilog(ncpus)), units: nanoseconds) * * This option delays the preemption effects of decoupled workloads * and reduces their over-scheduling. Synchronous workloads will still |