sched/numa: Drop sysctl_numa_balancing_settle_count sysctl

commit 887c290e (sched/numa: Decide whether to favour task or group weights
based on swap candidate relationships) drop the check against
sysctl_numa_balancing_settle_count, this patch remove the sysctl.

Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Link: http://lkml.kernel.org/r/1386833006-6600-1-git-send-email-liwanp@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Documentation/sysctl/kernel.txt

@@ -428,11 +428,6 @@ rate for each task.
 numa_balancing_scan_size_mb is how many megabytes worth of pages are
 scanned for a given scan.
 
-numa_balancing_settle_count is how many scan periods must complete before
-the schedule balancer stops pushing the task towards a preferred node. This
-gives the scheduler a chance to place the task on an alternative node if the
-preferred node is overloaded.
-
 numa_balancing_migrate_deferred is how many page migrations get skipped
 unconditionally, after a page migration is skipped because a page is shared
 with other tasks. This reduces page migration overhead, and determines

include/linux/sched/sysctl.h

@@ -48,7 +48,6 @@ extern unsigned int sysctl_numa_balancing_scan_delay;
 extern unsigned int sysctl_numa_balancing_scan_period_min;
 extern unsigned int sysctl_numa_balancing_scan_period_max;
 extern unsigned int sysctl_numa_balancing_scan_size;
-extern unsigned int sysctl_numa_balancing_settle_count;
 
 #ifdef CONFIG_SCHED_DEBUG
 extern unsigned int sysctl_sched_migration_cost;

kernel/sched/fair.c

@@ -872,15 +872,6 @@ static unsigned int task_scan_max(struct task_struct *p)
 	return max(smin, smax);
 }
 
-/*
- * Once a preferred node is selected the scheduler balancer will prefer moving
- * a task to that node for sysctl_numa_balancing_settle_count number of PTE
- * scans. This will give the process the chance to accumulate more faults on
- * the preferred node but still allow the scheduler to move the task again if
- * the nodes CPUs are overloaded.
- */
-unsigned int sysctl_numa_balancing_settle_count __read_mostly = 4;
-
 static void account_numa_enqueue(struct rq *rq, struct task_struct *p)
 {
 	rq->nr_numa_running += (p->numa_preferred_nid != -1);

kernel/sysctl.c

@@ -384,13 +384,6 @@ static struct ctl_table kern_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
-	{
-		.procname       = "numa_balancing_settle_count",
-		.data           = &sysctl_numa_balancing_settle_count,
-		.maxlen         = sizeof(unsigned int),
-		.mode           = 0644,
-		.proc_handler   = proc_dointvec,
-	},
 	{
 		.procname       = "numa_balancing_migrate_deferred",
 		.data           = &sysctl_numa_balancing_migrate_deferred,