Re: [PATCH] memcg: move do_memsw_account() to CONFIG_MEMCG_V1

[Johannes Weiner]

On Wed, Mar 12, 2025 at 03:25:52PM -0700, Shakeel Butt wrote:
> The do_memsw_account() is used to enable or disable legacy memory+swap
> accounting in memory cgroup. However with disabled CONFIG_MEMCG_V1, we
> don't need to keep checking it. So, let's always return false for
> !CONFIG_MEMCG_V1 configs.
> 
> Before the patch:
> 
> $ size mm/memcontrol.o
>    text    data     bss     dec     hex filename
>   49928   10736    4172   64836    fd44 mm/memcontrol.o
> 
> After the patch:
> 
> $ size mm/memcontrol.o
>    text    data     bss     dec     hex filename
>   49430   10480    4172   64082    fa52 mm/memcontrol.o
> 
> Signed-off-by: Shakeel Butt <shakeel.butt@xxxxxxxxx>

Nice. It being a jump label avoids the branch, but it's still
unnecessary text and therefor i$ burden on fairly hot paths.

Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>