[PATCH v3 2/2] xarray: honor XA_FLAGS_ACCOUNT in xas_split_alloc()

XArray operations that allocate xa_nodes, such as xas_nomem() and
xas_alloc(), add __GFP_ACCOUNT when the array has XA_FLAGS_ACCOUNT set.
This charges the allocated memory and avoids the workingset convergence
issue described by commit 7b785645e8f13 ("mm: fix page cache convergence
regression").

xas_split_alloc() does not add _GFP_ACCOUNT when XA_FLAGS_ACCOUNT is
present. Fix it.

Fixes: 6b24ca4a1a8d4 ("mm: Use multi-index entries in the page cache")
Reviewed-by: Lorenzo Stoakes (ARM) <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Signed-off-by: Zi Yan <[email protected]>
Cc: <[email protected]> # depends on mm-hotfixes-unstable patch: mm/huge_memory: initialise workingset state before folio split
---
 lib/xarray.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/xarray.c b/lib/xarray.c
index 9a8b4916540cf..bfe7bef80f34e 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -1053,6 +1053,9 @@ void xas_split_alloc(struct xa_state *xas, void *entry, unsigned int order,
 	if (xas->xa_shift + XA_CHUNK_SHIFT > order)
 		return;
 
+	if (xas->xa->xa_flags & XA_FLAGS_ACCOUNT)
+		gfp |= __GFP_ACCOUNT;
+
 	do {
 		struct xa_node *node;
 

-- 
2.53.0