mm: kmem: switch to static_branch_likely() in memcg_kmem_enabled()

Currently memcg_kmem_enabled() is optimized for the kernel memory
accounting being off.  It was so for a long time, and arguably the reason
behind was that the kernel memory accounting was initially an opt-in
feature.  However, now it's on by default on both cgroup v1 and cgroup v2,
and it's on for all cgroups.  So let's switch over to
static_branch_likely() to reflect this fact.

Unlikely there is a significant performance difference, as the cost of a
memory allocation and its accounting significantly exceeds the cost of a
jump.  However, the conversion makes the code look more logically.

Signed-off-by: Roman Gushchin <>
Signed-off-by: Andrew Morton <>
Reviewed-by: Shakeel Butt <>
Acked-by: Vlastimil Babka <>
Cc: Johannes Weiner <>
Cc: Michal Hocko <>
Cc: Christoph Lameter <>
Cc: David Rientjes <>
Cc: Joonsoo Kim <>
Cc: Pekka Enberg <>
Signed-off-by: Linus Torvalds <>
1 file changed