+ mm-zswap-convert-zswap_invalidate-to-take-a-range.patch added to mm-new branch

+ mm-zswap-convert-zswap_invalidate-to-take-a-range.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm: zswap: convert zswap_invalidate() to take a range
has been added to the -mm mm-new branch.  Its filename is
     mm-zswap-convert-zswap_invalidate-to-take-a-range.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-zswap-convert-zswap_invalidate-to-take-a-range.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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------------------------------------------------------
From: Kefeng Wang <wangkefeng.wang@huawei.com>
Subject: mm: zswap: convert zswap_invalidate() to take a range
Date: Thu, 10 Sep 2026 20:35:42 +0800

Patch series "mm: zswap: optimize zswap invalidate and store", v3.

This series range-ifies zswap_invalidate() to skip xarray lookups when
zswap is unused, and reuses it in zswap_store() to eliminate redundant
per-slot lookups and open-coded logic.


This patch (of 3):

zswap_invalidate() takes a swp_entry_t only to unpack it right back into
type and offset, and both callers already have those values in hand.  Pass
type, offset, and nr_entries directly so swap_range_free() can invalidate
an entire range in one call instead of looping in the caller.

Link: https://lore.kernel.org/20260910123544.818146-1-wangkefeng.wang@huawei.com
Link: https://lore.kernel.org/20260910123544.818146-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Yosry Ahmed <yosry@kernel.org>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Kairui Song <kasong@tencent.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/zswap.h |    8 ++++++--
 mm/swapfile.c         |    4 +---
 mm/zswap.c            |   29 +++++++++++++++++++----------
 3 files changed, 26 insertions(+), 15 deletions(-)

--- a/include/linux/zswap.h~mm-zswap-convert-zswap_invalidate-to-take-a-range
+++ a/include/linux/zswap.h
@@ -27,7 +27,7 @@ struct zswap_lruvec_state {
 unsigned long zswap_total_pages(void);
 bool zswap_store(struct folio *folio);
 int zswap_load(struct folio *folio);
-void zswap_invalidate(swp_entry_t swp);
+void zswap_invalidate(int type, pgoff_t offset, unsigned long nr_entries);
 int zswap_swapon(int type, unsigned long nr_pages);
 void zswap_swapoff(int type);
 void zswap_memcg_offline_cleanup(struct mem_cgroup *memcg);
@@ -49,7 +49,11 @@ static inline int zswap_load(struct foli
 	return -ENOENT;
 }
 
-static inline void zswap_invalidate(swp_entry_t swp) {}
+static inline void zswap_invalidate(int type, pgoff_t offset,
+		unsigned long nr_entries)
+{
+}
+
 static inline int zswap_swapon(int type, unsigned long nr_pages)
 {
 	return 0;
--- a/mm/swapfile.c~mm-zswap-convert-zswap_invalidate-to-take-a-range
+++ a/mm/swapfile.c
@@ -1316,10 +1316,8 @@ static void swap_range_free(struct swap_
 {
 	unsigned long end = offset + nr_entries - 1;
 	void (*swap_slot_free_notify)(struct block_device *, unsigned long);
-	unsigned int i;
 
-	for (i = 0; i < nr_entries; i++)
-		zswap_invalidate(swp_entry(si->type, offset + i));
+	zswap_invalidate(si->type, offset, nr_entries);
 
 	if (si->flags & SWP_BLKDEV)
 		swap_slot_free_notify =
--- a/mm/zswap.c~mm-zswap-convert-zswap_invalidate-to-take-a-range
+++ a/mm/zswap.c
@@ -228,10 +228,15 @@ static bool zswap_has_pool;
 /* One swap address space for each 64M swap space */
 #define ZSWAP_ADDRESS_SPACE_SHIFT 14
 #define ZSWAP_ADDRESS_SPACE_PAGES (1 << ZSWAP_ADDRESS_SPACE_SHIFT)
+
+static inline struct xarray *zswap_tree(int type, pgoff_t offset)
+{
+	return &zswap_trees[type][offset >> ZSWAP_ADDRESS_SPACE_SHIFT];
+}
+
 static inline struct xarray *swap_zswap_tree(swp_entry_t swp)
 {
-	return &zswap_trees[swp_type(swp)][swp_offset(swp)
-		>> ZSWAP_ADDRESS_SPACE_SHIFT];
+	return zswap_tree(swp_type(swp), swp_offset(swp));
 }
 
 #define zswap_pool_debug(msg, p)			\
@@ -1659,18 +1664,22 @@ int zswap_load(struct folio *folio)
 	return 0;
 }
 
-void zswap_invalidate(swp_entry_t swp)
+void zswap_invalidate(int type, pgoff_t offset, unsigned long nr_entries)
 {
-	pgoff_t offset = swp_offset(swp);
-	struct xarray *tree = swap_zswap_tree(swp);
 	struct zswap_entry *entry;
+	struct xarray *tree;
+	unsigned long i;
 
-	if (xa_empty(tree))
-		return;
+	for (i = 0; i < nr_entries; i++) {
+		tree = zswap_tree(type, offset + i);
 
-	entry = xa_erase(tree, offset);
-	if (entry)
-		zswap_entry_free(entry);
+		if (xa_empty(tree))
+			continue;
+
+		entry = xa_erase(tree, offset + i);
+		if (entry)
+			zswap_entry_free(entry);
+	}
 }
 
 int zswap_swapon(int type, unsigned long nr_pages)
_

Patches currently in -mm which might be from wangkefeng.wang@huawei.com are

xfs-remove-dead-kswapd-flag-inheritance-from-btree-split-worker.patch
iomap-simplify-writepages-reclaim-guard.patch
mm-replace-pf_kswapd-flag-with-kthread_func-check.patch
mm-replace-pf_kcompactd-flag-with-kthread_func-check.patch
mm-zswap-convert-zswap_invalidate-to-take-a-range.patch
mm-zswap-skip-xarray-walk-in-zswap_invalidate-when-zswap-is-unused.patch
mm-zswap-reuse-zswap_invalidate-in-zswap_store.patch