From 3b1d58a4c96799eb4c92039e1b851b86f853548a Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Wed, 28 Aug 2013 10:18:00 +1000 Subject: list_lru: per-node list infrastructure MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Now that we have an LRU list API, we can start to enhance the implementation. This splits the single LRU list into per-node lists and locks to enhance scalability. Items are placed on lists according to the node the memory belongs to. To make scanning the lists efficient, also track whether the per-node lists have entries in them in a active nodemask. Note: We use a fixed-size array for the node LRU, this struct can be very big if MAX_NUMNODES is big. If this becomes a problem this is fixable by turning this into a pointer and dynamically allocating this to nr_node_ids. This quantity is firwmare-provided, and still would provide room for all nodes at the cost of a pointer lookup and an extra allocation. Because that allocation will most likely come from a may very well fail. [glommer@openvz.org: fix warnings, added note about node lru] Signed-off-by: Dave Chinner Signed-off-by: Glauber Costa Reviewed-by: Greg Thelen Acked-by: Mel Gorman Cc: "Theodore Ts'o" Cc: Adrian Hunter Cc: Al Viro Cc: Artem Bityutskiy Cc: Arve Hjønnevåg Cc: Carlos Maiolino Cc: Christoph Hellwig Cc: Chuck Lever Cc: Daniel Vetter Cc: David Rientjes Cc: Gleb Natapov Cc: Greg Thelen Cc: J. Bruce Fields Cc: Jan Kara Cc: Jerome Glisse Cc: John Stultz Cc: KAMEZAWA Hiroyuki Cc: Kent Overstreet Cc: Kirill A. Shutemov Cc: Marcelo Tosatti Cc: Mel Gorman Cc: Steven Whitehouse Cc: Thomas Hellstrom Cc: Trond Myklebust Signed-off-by: Andrew Morton Signed-off-by: Al Viro --- mm/list_lru.c | 146 ++++++++++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 111 insertions(+), 35 deletions(-) (limited to 'mm') diff --git a/mm/list_lru.c b/mm/list_lru.c index dd74c5434cd8..1efe4ecc02b1 100644 --- a/mm/list_lru.c +++ b/mm/list_lru.c @@ -6,41 +6,73 @@ */ #include #include +#include #include bool list_lru_add(struct list_lru *lru, struct list_head *item) { - spin_lock(&lru->lock); + int nid = page_to_nid(virt_to_page(item)); + struct list_lru_node *nlru = &lru->node[nid]; + + spin_lock(&nlru->lock); + WARN_ON_ONCE(nlru->nr_items < 0); if (list_empty(item)) { - list_add_tail(item, &lru->list); - lru->nr_items++; - spin_unlock(&lru->lock); + list_add_tail(item, &nlru->list); + if (nlru->nr_items++ == 0) + node_set(nid, lru->active_nodes); + spin_unlock(&nlru->lock); return true; } - spin_unlock(&lru->lock); + spin_unlock(&nlru->lock); return false; } EXPORT_SYMBOL_GPL(list_lru_add); bool list_lru_del(struct list_lru *lru, struct list_head *item) { - spin_lock(&lru->lock); + int nid = page_to_nid(virt_to_page(item)); + struct list_lru_node *nlru = &lru->node[nid]; + + spin_lock(&nlru->lock); if (!list_empty(item)) { list_del_init(item); - lru->nr_items--; - spin_unlock(&lru->lock); + if (--nlru->nr_items == 0) + node_clear(nid, lru->active_nodes); + WARN_ON_ONCE(nlru->nr_items < 0); + spin_unlock(&nlru->lock); return true; } - spin_unlock(&lru->lock); + spin_unlock(&nlru->lock); return false; } EXPORT_SYMBOL_GPL(list_lru_del); -unsigned long list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate, - void *cb_arg, unsigned long nr_to_walk) +unsigned long list_lru_count(struct list_lru *lru) { + unsigned long count = 0; + int nid; + + for_each_node_mask(nid, lru->active_nodes) { + struct list_lru_node *nlru = &lru->node[nid]; + + spin_lock(&nlru->lock); + WARN_ON_ONCE(nlru->nr_items < 0); + count += nlru->nr_items; + spin_unlock(&nlru->lock); + } + + return count; +} +EXPORT_SYMBOL_GPL(list_lru_count); + +static unsigned long +list_lru_walk_node(struct list_lru *lru, int nid, list_lru_walk_cb isolate, + void *cb_arg, unsigned long *nr_to_walk) +{ + + struct list_lru_node *nlru = &lru->node[nid]; struct list_head *item, *n; - unsigned long removed = 0; + unsigned long isolated = 0; /* * If we don't keep state of at which pass we are, we can loop at * LRU_RETRY, since we have no guarantees that the caller will be able @@ -50,18 +82,20 @@ unsigned long list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate, */ bool first_pass = true; - spin_lock(&lru->lock); + spin_lock(&nlru->lock); restart: - list_for_each_safe(item, n, &lru->list) { + list_for_each_safe(item, n, &nlru->list) { enum lru_status ret; - ret = isolate(item, &lru->lock, cb_arg); + ret = isolate(item, &nlru->lock, cb_arg); switch (ret) { case LRU_REMOVED: - lru->nr_items--; - removed++; + if (--nlru->nr_items == 0) + node_clear(nid, lru->active_nodes); + WARN_ON_ONCE(nlru->nr_items < 0); + isolated++; break; case LRU_ROTATE: - list_move_tail(item, &lru->list); + list_move_tail(item, &nlru->list); break; case LRU_SKIP: break; @@ -76,42 +110,84 @@ restart: BUG(); } - if (nr_to_walk-- == 0) + if ((*nr_to_walk)-- == 0) break; } - spin_unlock(&lru->lock); - return removed; + + spin_unlock(&nlru->lock); + return isolated; +} +EXPORT_SYMBOL_GPL(list_lru_walk_node); + +unsigned long list_lru_walk(struct list_lru *lru, list_lru_walk_cb isolate, + void *cb_arg, unsigned long nr_to_walk) +{ + unsigned long isolated = 0; + int nid; + + for_each_node_mask(nid, lru->active_nodes) { + isolated += list_lru_walk_node(lru, nid, isolate, + cb_arg, &nr_to_walk); + if (nr_to_walk <= 0) + break; + } + return isolated; } EXPORT_SYMBOL_GPL(list_lru_walk); -unsigned long list_lru_dispose_all(struct list_lru *lru, - list_lru_dispose_cb dispose) +static unsigned long list_lru_dispose_all_node(struct list_lru *lru, int nid, + list_lru_dispose_cb dispose) { - unsigned long disposed = 0; + struct list_lru_node *nlru = &lru->node[nid]; LIST_HEAD(dispose_list); + unsigned long disposed = 0; - spin_lock(&lru->lock); - while (!list_empty(&lru->list)) { - list_splice_init(&lru->list, &dispose_list); - disposed += lru->nr_items; - lru->nr_items = 0; - spin_unlock(&lru->lock); + spin_lock(&nlru->lock); + while (!list_empty(&nlru->list)) { + list_splice_init(&nlru->list, &dispose_list); + disposed += nlru->nr_items; + nlru->nr_items = 0; + node_clear(nid, lru->active_nodes); + spin_unlock(&nlru->lock); dispose(&dispose_list); - spin_lock(&lru->lock); + spin_lock(&nlru->lock); } - spin_unlock(&lru->lock); + spin_unlock(&nlru->lock); return disposed; } +unsigned long list_lru_dispose_all(struct list_lru *lru, + list_lru_dispose_cb dispose) +{ + unsigned long disposed; + unsigned long total = 0; + int nid; + + do { + disposed = 0; + for_each_node_mask(nid, lru->active_nodes) { + disposed += list_lru_dispose_all_node(lru, nid, + dispose); + } + total += disposed; + } while (disposed != 0); + + return total; +} + int list_lru_init(struct list_lru *lru) { - spin_lock_init(&lru->lock); - INIT_LIST_HEAD(&lru->list); - lru->nr_items = 0; + int i; + nodes_clear(lru->active_nodes); + for (i = 0; i < MAX_NUMNODES; i++) { + spin_lock_init(&lru->node[i].lock); + INIT_LIST_HEAD(&lru->node[i].list); + lru->node[i].nr_items = 0; + } return 0; } EXPORT_SYMBOL_GPL(list_lru_init); -- cgit v1.2.3