The patch titled
Subject: mm/zswap: stop lru list shrinking when encounter warm region
has been added to the -mm mm-unstable branch. Its filename is
mm-zswap-stop-lru-list-shrinking-when-encounter-warm-region.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-zswap-stop-lru-list-shrinking-when-encounter-warm-region.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: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
Subject: mm/zswap: stop lru list shrinking when encounter warm region
Date: Sun, 04 Feb 2024 03:06:01 +0000
When the shrinker encounter an existing folio in swap cache, it means we
are shrinking into the warmer region. We should terminate shrinking if
we're in the dynamic shrinker context.
This patch add LRU_STOP to support this, to avoid overshrinking.
Link: https://lkml.kernel.org/r/20240201-b4-zswap-invalidate-entry-v2-3-99d4084260a0@xxxxxxxxxxxxx
Signed-off-by: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Acked-by: Nhat Pham <nphamcs@xxxxxxxxx>
Reviewed-by: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/list_lru.h | 2 ++
mm/list_lru.c | 3 +++
mm/zswap.c | 4 +++-
3 files changed, 8 insertions(+), 1 deletion(-)
--- a/include/linux/list_lru.h~mm-zswap-stop-lru-list-shrinking-when-encounter-warm-region
+++ a/include/linux/list_lru.h
@@ -24,6 +24,8 @@ enum lru_status {
LRU_SKIP, /* item cannot be locked, skip */
LRU_RETRY, /* item not freeable. May drop the lock
internally, but has to return locked. */
+ LRU_STOP, /* stop lru list walking. May drop the lock
+ internally, but has to return locked. */
};
struct list_lru_one {
--- a/mm/list_lru.c~mm-zswap-stop-lru-list-shrinking-when-encounter-warm-region
+++ a/mm/list_lru.c
@@ -243,6 +243,9 @@ restart:
*/
assert_spin_locked(&nlru->lock);
goto restart;
+ case LRU_STOP:
+ assert_spin_locked(&nlru->lock);
+ goto out;
default:
BUG();
}
--- a/mm/zswap.c~mm-zswap-stop-lru-list-shrinking-when-encounter-warm-region
+++ a/mm/zswap.c
@@ -1315,8 +1315,10 @@ static enum lru_status shrink_memcg_cb(s
* into the warmer region. We should terminate shrinking (if we're in the dynamic
* shrinker context).
*/
- if (writeback_result == -EEXIST && encountered_page_in_swapcache)
+ if (writeback_result == -EEXIST && encountered_page_in_swapcache) {
+ ret = LRU_STOP;
*encountered_page_in_swapcache = true;
+ }
} else {
zswap_written_back_pages++;
}
_
Patches currently in -mm which might be from zhouchengming@xxxxxxxxxxxxx are
mm-zswap-dont-return-lru_skip-if-we-have-dropped-lru-lock.patch
mm-zswap-make-sure-each-swapfile-always-have-zswap-rb-tree.patch
mm-zswap-split-zswap-rb-tree.patch
mm-zswap-fix-race-between-lru-writeback-and-swapoff.patch
mm-list_lru-remove-list_lru_putback.patch
mm-zswap-add-more-comments-in-shrink_memcg_cb.patch
mm-zswap-invalidate-zswap-entry-when-swap-entry-free.patch
mm-zswap-stop-lru-list-shrinking-when-encounter-warm-region.patch
mm-zswap-remove-duplicate_entry-debug-value.patch
mm-zswap-only-support-zswap_exclusive_loads_enabled.patch
mm-zswap-zswap-entry-doesnt-need-refcount-anymore.patch
