Re: [PATCH -mmotm 0/8] memcg: recharge at task move

KAMEZAWA Hiroyuki
2009-11-09T05:19:11Z

On Mon, 9 Nov 2009 10:44:46 +0900
Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> wrote:
> > Seems much nicer but I have some nitpicks as already commented.
> >
> > For [8/8], mm->swap_usage counter may be a help for making it faster.
> > Concern is how it's shared but will not be very big error.
> >
> will change as I mentioned in another mail.
>
> I'll repost 3 and 4 as cleanup(I think they are ready for inclusion),
> and post removal-of-memcg_tasklist as a separate patch.
>
> I'll postpone the body of this feature(waiting for your percpu change
> and per-process swap counter at least).
>
Thanks. I agree 1-4 are ready for merge. But, please get ack by Paul.
or Li zefan. Paul, Li, how do you think about [1/8] ?

> > > TODO:
> > > - add support for file cache, shmem/tmpfs, and shared(mapcount > 1) pages.
> > > - implement madvise(2) to let users decide the target vma for recharge.
> > >
> >
> > About this, I think "force_move_shared_account" flag is enough, I think.
> > But we have to clarify "mmap()ed but not on page table" entries are not
> > moved....
> >
> You mean swap entries of shmem/tmpfs, do you ? I agree they are hard to handle..
>
Yes and No. Including mmaped file.

>
> My concern is:
>
> - I want to add support for private file caches, shmes/tmpfs pages(including swaps of them),
> and "shared" pages by some means in future, and let an admin or a middle-ware
> decide how to handle them.
Yes, I agree that middle ware may want that.

> - Once this feature has been merged(at .33?), I don't want to change the behavior
> when a user set "recharge_at_immigrate=1".
> So, I'll "extend" the meaning of "recharge_at_immigrate" or add a new flag file
> to support other type of charges.

Yes, I think making recharge_at_immigrate as "bitmask" makes sense.
So, showing "recharge_at_immigrate" is a bitmask _now_ both in code and documentation
in clear way will be a help for future.

Thanks,
-Kame