diff options
| -rw-r--r-- | mm/list_lru.c | 29 |
1 files changed, 12 insertions, 17 deletions
diff --git a/mm/list_lru.c b/mm/list_lru.c index 1efe4ecc02b1..e77c29f4c243 100644 --- a/mm/list_lru.c +++ b/mm/list_lru.c @@ -73,19 +73,19 @@ list_lru_walk_node(struct list_lru *lru, int nid, list_lru_walk_cb isolate, struct list_lru_node *nlru = &lru->node[nid]; struct list_head *item, *n; 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 - * to do something other than retry on the next pass. We handle this by - * allowing at most one retry per object. This should not be altered - * by any condition other than LRU_RETRY. - */ - bool first_pass = true; spin_lock(&nlru->lock); restart: list_for_each_safe(item, n, &nlru->list) { enum lru_status ret; + + /* + * decrement nr_to_walk first so that we don't livelock if we + * get stuck on large numbesr of LRU_RETRY items + */ + if (--(*nr_to_walk) == 0) + break; + ret = isolate(item, &nlru->lock, cb_arg); switch (ret) { case LRU_REMOVED: @@ -100,19 +100,14 @@ restart: case LRU_SKIP: break; case LRU_RETRY: - if (!first_pass) { - first_pass = true; - break; - } - first_pass = false; + /* + * The lru lock has been dropped, our list traversal is + * now invalid and so we have to restart from scratch. + */ goto restart; default: BUG(); } - - if ((*nr_to_walk)-- == 0) - break; - } spin_unlock(&nlru->lock); |