Re: [PATCH 3/3] mm: kmem: switch to static_branch_likely() in memcg_kmem_enabled()

From: Shakeel Butt
Date: Tue Jul 07 2020 - 13:52:54 EST


On Tue, Jul 7, 2020 at 10:36 AM Roman Gushchin <guro@xxxxxx> wrote:
>
> 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 <guro@xxxxxx>

Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>