Merge branch 'linus' into sched/core, to resolve conflicts

[linux-drm-fsl-dcu.git] / mm / mempolicy.c

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index ae3c8f3595d4ff522f0427b05ace2f7e041da8ad..f520b9da9c1f156aaf5ec2713634570299608428 100644 (file)
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2301,35 +2301,6 @@ static void sp_free(struct sp_node *n)
        kmem_cache_free(sn_cache, n);
 }
 
-#ifdef CONFIG_NUMA_BALANCING
-static bool numa_migrate_deferred(struct task_struct *p, int last_cpupid)
-{
-       /* Never defer a private fault */
-       if (cpupid_match_pid(p, last_cpupid))
-               return false;
-
-       if (p->numa_migrate_deferred) {
-               p->numa_migrate_deferred--;
-               return true;
-       }
-       return false;
-}
-
-static inline void defer_numa_migrate(struct task_struct *p)
-{
-       p->numa_migrate_deferred = sysctl_numa_balancing_migrate_deferred;
-}
-#else
-static inline bool numa_migrate_deferred(struct task_struct *p, int last_cpupid)
-{
-       return false;
-}
-
-static inline void defer_numa_migrate(struct task_struct *p)
-{
-}
-#endif /* CONFIG_NUMA_BALANCING */
-
 /**
  * mpol_misplaced - check whether current page node is valid in policy
  *
@@ -2403,52 +2374,9 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long
 
        /* Migrate the page towards the node whose CPU is referencing it */
        if (pol->flags & MPOL_F_MORON) {
-               int last_cpupid;
-               int this_cpupid;
-
                polnid = thisnid;
-               this_cpupid = cpu_pid_to_cpupid(thiscpu, current->pid);
-
-               /*
-                * Multi-stage node selection is used in conjunction
-                * with a periodic migration fault to build a temporal
-                * task<->page relation. By using a two-stage filter we
-                * remove short/unlikely relations.
-                *
-                * Using P(p) ~ n_p / n_t as per frequentist
-                * probability, we can equate a task's usage of a
-                * particular page (n_p) per total usage of this
-                * page (n_t) (in a given time-span) to a probability.
-                *
-                * Our periodic faults will sample this probability and
-                * getting the same result twice in a row, given these
-                * samples are fully independent, is then given by
-                * P(n)^2, provided our sample period is sufficiently
-                * short compared to the usage pattern.
-                *
-                * This quadric squishes small probabilities, making
-                * it less likely we act on an unlikely task<->page
-                * relation.
-                */
-               last_cpupid = page_cpupid_xchg_last(page, this_cpupid);
-               if (!cpupid_pid_unset(last_cpupid) && cpupid_to_nid(last_cpupid) != thisnid) {
 
-                       /* See sysctl_numa_balancing_migrate_deferred comment */
-                       if (!cpupid_match_pid(current, last_cpupid))
-                               defer_numa_migrate(current);
-
-                       goto out;
-               }
-
-               /*
-                * The quadratic filter above reduces extraneous migration
-                * of shared pages somewhat. This code reduces it even more,
-                * reducing the overhead of page migrations of shared pages.
-                * This makes workloads with shared pages rely more on
-                * "move task near its memory", and less on "move memory
-                * towards its task", which is exactly what we want.
-                */
-               if (numa_migrate_deferred(current, last_cpupid))
+               if (!should_numa_migrate_memory(current, page, curnid, thiscpu))
                        goto out;
        }