During swapoff, try_to_unuse() makes sure that zswap_invalidate() is called for all swap entries before zswap_swapoff() is called. This means that all zswap entries should already be removed from the tree. Simplify zswap_swapoff() by removing the trees cleanup code, and leave an assertion in its place. Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx> --- mm/zswap.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) diff --git a/mm/zswap.c b/mm/zswap.c index dcdd5ecfedb09..78df16d307aa8 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -1808,19 +1808,9 @@ void zswap_swapoff(int type) if (!trees) return; - for (i = 0; i < nr_zswap_trees[type]; i++) { - struct zswap_tree *tree = trees + i; - struct zswap_entry *entry, *n; - - /* walk the tree and free everything */ - spin_lock(&tree->lock); - rbtree_postorder_for_each_entry_safe(entry, n, - &tree->rbroot, - rbnode) - zswap_free_entry(entry); - tree->rbroot = RB_ROOT; - spin_unlock(&tree->lock); - } + /* try_to_unuse() invalidated all the entries already */ + for (i = 0; i < nr_zswap_trees[type]; i++) + WARN_ON_ONCE(!RB_EMPTY_ROOT(&trees[i].rbroot)); kvfree(trees); nr_zswap_trees[type] = 0; -- 2.43.0.429.g432eaa2c6b-goog