[01/11] memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT

Commit Message

Andrew Morton Oct. 28, 2021, 9:36 p.m. UTC

From: Shakeel Butt <[e-mail]>
Subject: memcg: page_alloc: skip bulk allocator for __GFP_ACCOUNT

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.

Link: https://lkml.kernel.org/r/[e-mail]
Fixes: 5c1f4e690eec ("mm/vmalloc: switch to bulk allocator in __vmalloc_area_node()")
Signed-off-by: Shakeel Butt <[e-mail]>
Reported-by: Vasily Averin <[e-mail]>
Tested-by: Vasily Averin <[e-mail]>
Acked-by: David Hildenbrand <[e-mail]>
Acked-by: Michal Hocko <[e-mail]>
Acked-by: Roman Gushchin <[e-mail]>
Acked-by: Johannes Weiner <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/page_alloc.c |    4 ++++
 1 file changed, 4 insertions(+)

Patch

--- a/mm/page_alloc.c~memcg-page_alloc-skip-bulk-allocator-for-__gfp_account
+++ a/mm/page_alloc.c
@@ -5223,6 +5223,10 @@  unsigned long __alloc_pages_bulk(gfp_t g
 	if (unlikely(page_array && nr_pages - nr_populated == 0))
 		goto out;
 
+	/* Bulk allocator does not support memcg accounting. */
+	if (memcg_kmem_enabled() && (gfp & __GFP_ACCOUNT))
+		goto failed;
+
 	/* Use the single page allocator for one page. */
 	if (nr_pages - nr_populated == 1)
 		goto failed;