Re: [PATCH RFC 1/2] mm: kmem: optimize get_obj_cgroup_from_current()

From: Roman Gushchin
Date: Tue Dec 20 2022 - 16:15:38 EST


On Tue, Dec 20, 2022 at 11:55:34AM -0800, Shakeel Butt wrote:
> On Tue, Dec 20, 2022 at 10:28 AM Roman Gushchin
> <roman.gushchin@xxxxxxxxx> wrote:
> >
> > Manually inline memcg_kmem_bypass() and active_memcg() to speed up
> > get_obj_cgroup_from_current() by avoiding duplicate in_task() checks
> > and active_memcg() readings.
> >
> > Also add a likely() macro to __get_obj_cgroup_from_memcg():
> > obj_cgroup_tryget() should succeed at almost all times except
> > a very unlikely race with the memcg deletion path.
> >
> > Signed-off-by: Roman Gushchin <roman.gushchin@xxxxxxxxx>
>
> Can you please add your performance experiment setup and result of
> this patch in the commit description of this patch as well?

Sure. I used a small hack to just do a bunch of allocations in a raw
and measured the time. Will include it into the commit message.

Also will fix the #ifdef thing from the second patch, thanks for spotting
it.

>
> Acked-by: Shakeel Butt <shakeelb@xxxxxxxxxx>

Thank you for taking a look!