Commit 2b4d5b25 authored by Ingo Molnar's avatar Ingo Molnar

sched/fair: Clean up the tunable parameter definitions

No change in functionality:

 - align the default values vertically to make them easier to scan
 - standardize the 'default:' lines
 - fix minor whitespace typos
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 176cedc4
......@@ -37,7 +37,6 @@
/*
* Targeted preemption latency for CPU-bound tasks:
* (default: 6ms * (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
......@@ -46,31 +45,35 @@
*
* (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)
*/
unsigned int sysctl_sched_latency = 6000000ULL;
unsigned int normalized_sysctl_sched_latency = 6000000ULL;
unsigned int sysctl_sched_latency = 6000000ULL;
unsigned int normalized_sysctl_sched_latency = 6000000ULL;
/*
* The initial- and re-scaling of tunables is configurable
* (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus))
*
* Options are:
* SCHED_TUNABLESCALING_NONE - unscaled, always *1
* SCHED_TUNABLESCALING_LOG - scaled logarithmical, *1+ilog(ncpus)
* SCHED_TUNABLESCALING_LINEAR - scaled linear, *ncpus
*
* SCHED_TUNABLESCALING_NONE - unscaled, always *1
* SCHED_TUNABLESCALING_LOG - scaled logarithmical, *1+ilog(ncpus)
* SCHED_TUNABLESCALING_LINEAR - scaled linear, *ncpus
*
* (default SCHED_TUNABLESCALING_LOG = *(1+ilog(ncpus))
*/
enum sched_tunable_scaling sysctl_sched_tunable_scaling
= SCHED_TUNABLESCALING_LOG;
enum sched_tunable_scaling sysctl_sched_tunable_scaling = SCHED_TUNABLESCALING_LOG;
/*
* Minimal preemption granularity for CPU-bound tasks:
*
* (default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds)
*/
unsigned int sysctl_sched_min_granularity = 750000ULL;
unsigned int normalized_sysctl_sched_min_granularity = 750000ULL;
unsigned int sysctl_sched_min_granularity = 750000ULL;
unsigned int normalized_sysctl_sched_min_granularity = 750000ULL;
/*
* is kept at sysctl_sched_latency / sysctl_sched_min_granularity
* This value is kept at sysctl_sched_latency/sysctl_sched_min_granularity
*/
static unsigned int sched_nr_latency = 8;
......@@ -82,16 +85,17 @@ unsigned int sysctl_sched_child_runs_first __read_mostly;
/*
* SCHED_OTHER wake-up granularity.
* (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
*
* This option delays the preemption effects of decoupled workloads
* and reduces their over-scheduling. Synchronous workloads will still
* have immediate wakeup/sleep latencies.
*
* (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds)
*/
unsigned int sysctl_sched_wakeup_granularity = 1000000UL;
unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL;
unsigned int sysctl_sched_wakeup_granularity = 1000000UL;
unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL;
const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
#ifdef CONFIG_CFS_BANDWIDTH
/*
......@@ -102,16 +106,18 @@ const_debug unsigned int sysctl_sched_migration_cost = 500000UL;
* to consumption or the quota being specified to be smaller than the slice)
* we will always only issue the remaining available time.
*
* default: 5 msec, units: microseconds
*/
unsigned int sysctl_sched_cfs_bandwidth_slice = 5000UL;
* (default: 5 msec, units: microseconds)
*/
unsigned int sysctl_sched_cfs_bandwidth_slice = 5000UL;
#endif
/*
* The margin used when comparing utilization with CPU capacity:
* util * margin < capacity * 1024
*
* (default: ~20%)
*/
unsigned int capacity_margin = 1280; /* ~20% */
unsigned int capacity_margin = 1280;
static inline void update_load_add(struct load_weight *lw, unsigned long inc)
{
......@@ -7174,8 +7180,8 @@ check_cpu_capacity(struct rq *rq, struct sched_domain *sd)
* cpumask covering 1 cpu of the first group and 3 cpus of the second group.
* Something like:
*
* { 0 1 2 3 } { 4 5 6 7 }
* * * * *
* { 0 1 2 3 } { 4 5 6 7 }
* * * * *
*
* If we were to balance group-wise we'd place two tasks in the first group and
* two tasks in the second group. Clearly this is undesired as it will overload
......
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