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-rw-r--r--mm/mempolicy.c74
1 files changed, 1 insertions, 73 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index eeb2e3d2c962..4755c8576942 100644
--- 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;
}