[PATCH] memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT

From: Shakeel Butt
Date: Wed Oct 13 2021 - 15:43:55 EST


The commit 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in
__vmalloc_area_node()") switched to bulk page allocator for order 0
allocation backing vmalloc. However bulk page allocator does not support
__GFP_ACCOUNT allocations and there are several users of
kvmalloc(__GFP_ACCOUNT).

For now make __GFP_ACCOUNT allocations bypass bulk page allocator. In
future if there is workload that can be significantly improved with the
bulk page allocator with __GFP_ACCCOUNT support, we can revisit the
decision.

Fixes: 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in __vmalloc_area_node()")
Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
---
mm/page_alloc.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 668edb16446a..b3acad4615d3 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5215,6 +5215,10 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
unsigned int alloc_flags = ALLOC_WMARK_LOW;
int nr_populated = 0, nr_account = 0;

+ /* Bulk allocator does not support memcg accounting. */
+ if (unlikely(gfp & __GFP_ACCOUNT))
+ goto out;
+
/*
* Skip populated array elements to determine if any pages need
* to be allocated before disabling IRQs.
--
2.33.0.882.g93a45727a2-goog