The patch titled
Subject: mm: zswap: remove unnecessary trees cleanups in zswap_swapoff()
has been added to the -mm mm-unstable branch. Its filename is
mm-zswap-remove-unnecessary-trees-cleanups-in-zswap_swapoff.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-zswap-remove-unnecessary-trees-cleanups-in-zswap_swapoff.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Subject: mm: zswap: remove unnecessary trees cleanups in zswap_swapoff()
Date: Wed, 24 Jan 2024 04:51:12 +0000
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.
Link: https://lkml.kernel.org/r/20240124045113.415378-3-yosryahmed@xxxxxxxxxx
Signed-off-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Reviewed-by: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
Cc: Chris Li <chrisl@xxxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Nhat Pham <nphamcs@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/zswap.c | 16 +++-------------
1 file changed, 3 insertions(+), 13 deletions(-)
--- a/mm/zswap.c~mm-zswap-remove-unnecessary-trees-cleanups-in-zswap_swapoff
+++ a/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;
_
Patches currently in -mm which might be from yosryahmed@xxxxxxxxxx are
maintainers-supplement-of-zswap-maintainers-update.patch
mm-swap-enforce-updating-inuse_pages-at-the-end-of-swap_range_free.patch
mm-zswap-remove-unnecessary-trees-cleanups-in-zswap_swapoff.patch
