From 722aab0c3bbd7648d66790515c14d95d10a15bf3 Mon Sep 17 00:00:00 2001 From: Zou Nan hai Date: Mon, 26 Nov 2007 21:21:49 +0100 Subject: [PATCH] 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 Signed-off-by: Ingo Molnar --- kernel/sched_fair.c | 12 ++++++------ 1 file 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 -- 2.39.5