[PATCH slab/for-next 03/14] lib/xarray: specify SLAB_MAY_ACCOUNT for radix_tree_node cache
From: Harry Yoo (Meta)
Date: Wed Oct 21 2026 - 07:52:00 EST
XArrays with XA_FLAGS_ACCOUNT (e.g. the page cache) allocate nodes with
__GFP_ACCOUNT, and xarray/IDR callers can also pass GFP_KERNEL_ACCOUNT
directly. Specify SLAB_MAY_ACCOUNT when the object may be charged to a
memcg. __GFP_ACCOUNT without SLAB_MAY_ACCOUNT will not be allowed.
Path: __filemap_add_folio() (i_pages has XA_FLAGS_ACCOUNT)
-> xas_store() -> xas_alloc() (gfp |= __GFP_ACCOUNT)
-> kmem_cache_alloc_lru(radix_tree_node_cachep)
Assisted-by: LLM
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: linux-fsdevel@xxxxxxxxxxxxxxx
Signed-off-by: Harry Yoo (Meta) <harry@xxxxxxxxxx>
---
lib/radix-tree.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 976b9bd02a1b..2c7531deb0df 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -1600,7 +1600,7 @@ void __init radix_tree_init(void)
BUILD_BUG_ON(XA_CHUNK_SIZE > 255);
radix_tree_node_cachep = kmem_cache_create("radix_tree_node",
sizeof(struct radix_tree_node), 0,
- SLAB_PANIC | SLAB_RECLAIM_ACCOUNT,
+ SLAB_PANIC | SLAB_RECLAIM_ACCOUNT | SLAB_MAY_ACCOUNT,
radix_tree_node_ctor);
ret = cpuhp_setup_state_nocalls(CPUHP_RADIX_DEAD, "lib/radix:dead",
NULL, radix_tree_cpu_dead);
--
2.54.0