mm: numa: slow PTE scan rate if migration failures occur

[karo-tx-linux.git] / kernel / sched / fair.c

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 7ce18f3c097ac4779eb4cf6ed0ad14ac1beb3eb5..bcfe32088b3768363c2f37502a953b61a361f7ff 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1609,9 +1609,11 @@ static void update_task_scan_period(struct task_struct *p,
        /*
         * If there were no record hinting faults then either the task is
         * completely idle or all activity is areas that are not of interest
-        * to automatic numa balancing. Scan slower
+        * to automatic numa balancing. Related to that, if there were failed
+        * migration then it implies we are migrating too quickly or the local
+        * node is overloaded. In either case, scan slower
         */
-       if (local + shared == 0) {
+       if (local + shared == 0 || p->numa_faults_locality[2]) {
                p->numa_scan_period = min(p->numa_scan_period_max,
                        p->numa_scan_period << 1);
 
@@ -2080,6 +2082,8 @@ void task_numa_fault(int last_cpupid, int mem_node, int pages, int flags)
 
        if (migrated)
                p->numa_pages_migrated += pages;
+       if (flags & TNF_MIGRATE_FAIL)
+               p->numa_faults_locality[2] += pages;
 
        p->numa_faults[task_faults_idx(NUMA_MEMBUF, mem_node, priv)] += pages;
        p->numa_faults[task_faults_idx(NUMA_CPUBUF, cpu_node, priv)] += pages;