diff options
Diffstat (limited to 'mm/migrate.c')
| -rw-r--r-- | mm/migrate.c | 30 |
1 files changed, 29 insertions, 1 deletions
diff --git a/mm/migrate.c b/mm/migrate.c index 23bba5d..4b8267f 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1461,12 +1461,21 @@ static struct page *alloc_misplaced_dst_page(struct page *page, } /* + * page migration rate limiting control. + * Do not migrate more than @pages_to_migrate in a @migrate_interval_millisecs + * window of time. Default here says do not migrate more than 1280M per second. + */ +static unsigned int migrate_interval_millisecs __read_mostly = 100; +static unsigned int ratelimit_pages __read_mostly = 128 << (20 - PAGE_SHIFT); + +/* * Attempt to migrate a misplaced page to the specified destination * node. Caller is expected to have an elevated reference count on * the page that will be dropped by this function before returning. */ int migrate_misplaced_page(struct page *page, int node) { + pg_data_t *pgdat = NODE_DATA(node); int isolated = 0; LIST_HEAD(migratepages); @@ -1479,8 +1488,27 @@ int migrate_misplaced_page(struct page *page, int node) goto out; } + /* + * Rate-limit the amount of data that is being migrated to a node. + * Optimal placement is no good if the memory bus is saturated and + * all the time is being spent migrating! + */ + spin_lock(&pgdat->numabalancing_migrate_lock); + if (time_after(jiffies, pgdat->numabalancing_migrate_next_window)) { + pgdat->numabalancing_migrate_nr_pages = 0; + pgdat->numabalancing_migrate_next_window = jiffies + + msecs_to_jiffies(migrate_interval_millisecs); + } + if (pgdat->numabalancing_migrate_nr_pages > ratelimit_pages) { + spin_unlock(&pgdat->numabalancing_migrate_lock); + put_page(page); + goto out; + } + pgdat->numabalancing_migrate_nr_pages++; + spin_unlock(&pgdat->numabalancing_migrate_lock); + /* Avoid migrating to a node that is nearly full */ - if (migrate_balanced_pgdat(NODE_DATA(node), 1)) { + if (migrate_balanced_pgdat(pgdat, 1)) { int page_lru; if (isolate_lru_page(page)) { |