diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/mempolicy.c | 74 |
1 files changed, 1 insertions, 73 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index ae3c8f3595d4..f520b9da9c1f 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; } |