zpool_malloc_support_movable() always returns true for zsmalloc, the
only remaining zpool driver. Remove it and set the gfp flags in
zswap_compress() accordingly. Opportunistically use GFP_NOWAIT instead
of __GFP_NOWARN | __GFP_KSWAPD_RECLAIM for conciseness as they are
equivalent.

Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>
---
 include/linux/zpool.h |  3 ---
 mm/zpool.c            | 16 ----------------
 mm/zsmalloc.c         |  1 -
 mm/zswap.c            |  4 +---
 4 files changed, 1 insertion(+), 23 deletions(-)

diff --git a/include/linux/zpool.h b/include/linux/zpool.h
index 2c8a9d2654f6f..52f30e526607f 100644
--- a/include/linux/zpool.h
+++ b/include/linux/zpool.h
@@ -21,8 +21,6 @@ const char *zpool_get_type(struct zpool *pool);
 
 void zpool_destroy_pool(struct zpool *pool);
 
-bool zpool_malloc_support_movable(struct zpool *pool);
-
 int zpool_malloc(struct zpool *pool, size_t size, gfp_t gfp,
 			unsigned long *handle);
 
@@ -65,7 +63,6 @@ struct zpool_driver {
 	void *(*create)(const char *name, gfp_t gfp);
 	void (*destroy)(void *pool);
 
-	bool malloc_support_movable;
 	int (*malloc)(void *pool, size_t size, gfp_t gfp,
 				unsigned long *handle);
 	void (*free)(void *pool, unsigned long handle);
diff --git a/mm/zpool.c b/mm/zpool.c
index 4fc665b42f5e9..6d6d889309324 100644
--- a/mm/zpool.c
+++ b/mm/zpool.c
@@ -220,22 +220,6 @@ const char *zpool_get_type(struct zpool *zpool)
 	return zpool->driver->type;
 }
 
-/**
- * zpool_malloc_support_movable() - Check if the zpool supports
- *	allocating movable memory
- * @zpool:	The zpool to check
- *
- * This returns if the zpool supports allocating movable memory.
- *
- * Implementations must guarantee this to be thread-safe.
- *
- * Returns: true if the zpool supports allocating movable memory, false if not
- */
-bool zpool_malloc_support_movable(struct zpool *zpool)
-{
-	return zpool->driver->malloc_support_movable;
-}
-
 /**
  * zpool_malloc() - Allocate memory
  * @zpool:	The zpool to allocate from.
diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index cd1c2a8ffef05..961b270f023c2 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -503,7 +503,6 @@ static struct zpool_driver zs_zpool_driver = {
 	.owner =		  THIS_MODULE,
 	.create =		  zs_zpool_create,
 	.destroy =		  zs_zpool_destroy,
-	.malloc_support_movable = true,
 	.malloc =		  zs_zpool_malloc,
 	.free =			  zs_zpool_free,
 	.obj_read_begin =	  zs_zpool_obj_read_begin,
diff --git a/mm/zswap.c b/mm/zswap.c
index 4c474b692828d..138b50ba832b8 100644
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -964,9 +964,7 @@ static bool zswap_compress(struct page *page, struct zswap_entry *entry,
 		goto unlock;
 
 	zpool = pool->zpool;
-	gfp = __GFP_NORETRY | __GFP_NOWARN | __GFP_KSWAPD_RECLAIM;
-	if (zpool_malloc_support_movable(zpool))
-		gfp |= __GFP_HIGHMEM | __GFP_MOVABLE;
+	gfp = GFP_NOWAIT | __GFP_NORETRY | __GFP_HIGHMEM | __GFP_MOVABLE;
 	alloc_ret = zpool_malloc(zpool, dlen, gfp, &handle);
 	if (alloc_ret)
 		goto unlock;
-- 
2.48.1.711.g2feabab25a-goog

On Tue, Mar 4, 2025 at 10:12 PM Yosry Ahmed <yosry.ahmed@linux.dev> wrote:
>
> zpool_malloc_support_movable() always returns true for zsmalloc, the
> only remaining zpool driver. Remove it and set the gfp flags in
> zswap_compress() accordingly. Opportunistically use GFP_NOWAIT instead
> of __GFP_NOWARN | __GFP_KSWAPD_RECLAIM for conciseness as they are
> equivalent.
>
> Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>

Acked-by: Nhat Pham <nphamcs@gmail.com>

On Wed, Mar 05, 2025 at 06:11:33AM +0000, Yosry Ahmed wrote:
> zpool_malloc_support_movable() always returns true for zsmalloc, the
> only remaining zpool driver. Remove it and set the gfp flags in
> zswap_compress() accordingly. Opportunistically use GFP_NOWAIT instead
> of __GFP_NOWARN | __GFP_KSWAPD_RECLAIM for conciseness as they are
> equivalent.
> 
> Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>

On (25/03/05 06:11), Yosry Ahmed wrote:
> zpool_malloc_support_movable() always returns true for zsmalloc, the
> only remaining zpool driver. Remove it and set the gfp flags in
> zswap_compress() accordingly. Opportunistically use GFP_NOWAIT instead
> of __GFP_NOWARN | __GFP_KSWAPD_RECLAIM for conciseness as they are
> equivalent.
> 
> Signed-off-by: Yosry Ahmed <yosry.ahmed@linux.dev>

Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>