The patch titled
Subject: mm-zswap-cleanup-zswap_reclaim_entry-fix
has been added to the -mm mm-unstable branch. Its filename is
mm-zswap-cleanup-zswap_reclaim_entry-fix.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-zswap-cleanup-zswap_reclaim_entry-fix.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: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Subject: mm-zswap-cleanup-zswap_reclaim_entry-fix
Date: Thu Dec 14 02:21:39 PM PST 2023
retain comment, per Yosry
Cc: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
Cc: Chris Li <chriscli@xxxxxxxxxx>
Cc: Dan Streetman <ddstreet@xxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Nhat Pham <nphamcs@xxxxxxxxx>
Cc: Seth Jennings <sjenning@xxxxxxxxxx>
Cc: Vitaly Wool <vitaly.wool@xxxxxxxxxxxx>
Cc: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/zswap.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
--- a/mm/zswap.c~mm-zswap-cleanup-zswap_reclaim_entry-fix
+++ a/mm/zswap.c
@@ -1457,8 +1457,14 @@ static int zswap_writeback_entry(struct
mpol = get_task_policy(current);
page = __read_swap_cache_async(swpentry, GFP_KERNEL, mpol,
NO_INTERLEAVE_INDEX, &page_was_allocated, true);
- if (!page)
+ if (!page) {
+ /*
+ * If we get here because the page is already in swapcache, a
+ * load may be happening concurrently. It is safe and okay to
+ * not free the entry. It is also okay to return !0.
+ */
return -ENOMEM;
+ }
/* Found an existing page, we raced with load/swapin */
if (!page_was_allocated) {
_
Patches currently in -mm which might be from akpm@xxxxxxxxxxxxxxxxxxxx are
lib-maple_treec-fix-build-error-due-to-hotfix-alteration.patch
mm-list_lruc-remove-unused-list_lru_from_kmem.patch
mm-memcg-restore-subtree-stats-flushing-fix.patch
mm-zswap-cleanup-zswap_reclaim_entry-fix.patch
mips-fix-r3k_cache_init-build-regression-fix.patch
