From 250ba4a23f392dd37c673fd3879c6281a3a62291 Mon Sep 17 00:00:00 2001 From: Masahito S Date: Mon, 15 May 2023 06:00:52 +0900 Subject: [PATCH] constgran vanilla-max sched: Make latency / granularity constant tunable_scaling = 1 (logarithmic) -> 0 (constant) latency_ns = variable 6-24ms -> constant 24ms min_granularity_ns = variable 0.75-3ms -> constant 3ms wakeup_granularity_ns = variable 1-4ms -> constant 4ms --- kernel/sched/fair.c | 31 +++++++++++++++++++++++++++---- 1 file changed, 27 insertions(+), 4 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 8b5bf7280..340f8dd14 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -36,10 +36,16 @@ * (to see the precise effective timeslice length of your workload, * run vmstat and monitor the context-switches (cs) field) * - * (default: 6ms * (1 + ilog(ncpus)), units: nanoseconds) + * (BORE default: 24ms constant, units: nanoseconds) + * (CFS default: 6ms * (1 + ilog(ncpus)), units: nanoseconds) */ +#ifdef CONFIG_SCHED_BORE +unsigned int sysctl_sched_latency = 24000000ULL; +static unsigned int normalized_sysctl_sched_latency = 24000000ULL; +#else // CONFIG_SCHED_BORE unsigned int sysctl_sched_latency = 6000000ULL; static unsigned int normalized_sysctl_sched_latency = 6000000ULL; +#endif // CONFIG_SCHED_BORE /* * The initial- and re-scaling of tunables is configurable @@ -50,17 +56,28 @@ static unsigned int normalized_sysctl_sched_latency = 6000000ULL; * SCHED_TUNABLESCALING_LOG - scaled logarithmical, *1+ilog(ncpus) * SCHED_TUNABLESCALING_LINEAR - scaled linear, *ncpus * - * (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus)) + * (BORE default SCHED_TUNABLESCALING_NONE = *1 constant) + * (CFS default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus)) */ +#ifdef CONFIG_SCHED_BORE +unsigned int sysctl_sched_tunable_scaling = SCHED_TUNABLESCALING_NONE; +#else // CONFIG_SCHED_BORE unsigned int sysctl_sched_tunable_scaling = SCHED_TUNABLESCALING_LOG; +#endif // CONFIG_SCHED_BORE /* * Minimal preemption granularity for CPU-bound tasks: * - * (default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds) + * (BORE default: 3 msec constant, units: nanoseconds) + * (CFS default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds) */ +#ifdef CONFIG_SCHED_BORE +unsigned int sysctl_sched_min_granularity = 3000000ULL; +static unsigned int normalized_sysctl_sched_min_granularity = 3000000ULL; +#else // CONFIG_SCHED_BORE unsigned int sysctl_sched_min_granularity = 750000ULL; static unsigned int normalized_sysctl_sched_min_granularity = 750000ULL; +#endif // CONFIG_SCHED_BORE /* * This value is kept at sysctl_sched_latency/sysctl_sched_min_granularity @@ -80,10 +97,16 @@ unsigned int sysctl_sched_child_runs_first __read_mostly; * and reduces their over-scheduling. Synchronous workloads will still * have immediate wakeup/sleep latencies. * - * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds) + * (BORE default: 4 msec constant, units: nanoseconds) + * (CFS default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds) */ +#ifdef CONFIG_SCHED_BORE +unsigned int sysctl_sched_wakeup_granularity = 4000000UL; +static unsigned int normalized_sysctl_sched_wakeup_granularity = 4000000UL; +#else // CONFIG_SCHED_BORE unsigned int sysctl_sched_wakeup_granularity = 1000000UL; static unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL; +#endif // CONFIG_SCHED_BORE const_debug unsigned int sysctl_sched_migration_cost = 500000UL; -- 2.25.1