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>

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 02605f2826a2c2788cea41a9dd2eb000a169f0c0..aa475896782d4f52d4b689a7b6accfb0db5c0e57 100644 (file)
--- 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