[RFC 0/3] get rid of mm_struct::owner

Michal Hocko
2015-05-26T14:13:44Z

Hi,
this small series drops IMO awkward mm_struct::owner field which is
used to track task which owns the mm_struct and which is then used for
mm->mem_cgroup mapping. The motivation for the change and drawback
(namely user visible change of behavior) is described in the patch 3.

The first patch is a trivial cleanup by Tejun
(http://marc.info/?l=linux-mm&m=143197860820270) and I have added it
here just to prevent from conflicts with his changes.

Patch 2 is preparatory and it shouldn't cause any functional changes.
It simply replaces mc.to as an indicator of the charge migration
during task move by using mc.moving_task because we need to have mc.to
available even when the charges are not migrated.

I am sending this as an RFC because of the user visible aspect of the
change. I am not convinced that there is a strong usecase to justify
keeping mm->owner but I would like to hear back first.