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authorIngo Molnar <mingo@kernel.org>2016-11-23 07:37:00 +0100
committerIngo Molnar <mingo@kernel.org>2016-11-23 10:38:55 +0100
commit2b4d5b2582deffb77b3b4b48a59cd36e9e1e14d9 (patch)
treeb183c223cedd32785ef90ea34e4d7be282ddee7a /kernel/sched
parent176cedc4ed143745708999155c11b5717cdebb35 (diff)
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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: Peter 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: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
-rw-r--r--kernel/sched/fair.c50
1 files changed, 28 insertions, 22 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 02605f2826a2..aa475896782d 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -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