On Sun, Sep 13, 2020 at 7:45 PM Waiman Long <longman@xxxxxxxxxx> wrote: > > The swap page counter is v2 only while memsw is v1 only. As v1 and v2 > controllers cannot be active at the same time, there is no point to keep > both swap and memsw page counters in mem_cgroup. The previous patch has > made sure that memsw page counter is updated and accessed only when in > v1 code paths. So it is now safe to alias the v1 memsw page counter to v2 > swap page counter. This saves 14 long's in the size of mem_cgroup. This > is a saving of 112 bytes for 64-bit archs. > > While at it, also document which page counters are used in v1 and/or v2. > > Signed-off-by: Waiman Long <longman@xxxxxxxxxx> Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
