Messages in this thread | | | Date | Wed, 28 Jul 2010 11:44:02 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [RFC][PATCH 4/7][memcg] memcg use ID in page_cgroup |
| |
On Tue, 27 Jul 2010 22:39:04 -0400 Vivek Goyal <vgoyal@redhat.com> wrote:
> On Tue, Jul 27, 2010 at 04:56:29PM +0900, KAMEZAWA Hiroyuki wrote: > > From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> > > > > Now, addresses of memory cgroup can be calculated by their ID without complex. > > This patch relplaces pc->mem_cgroup from a pointer to a unsigned short. > > On 64bit architecture, this offers us more 6bytes room per page_cgroup. > > Use 2bytes for blkio-cgroup's page tracking. More 4bytes will be used for > > some light-weight concurrent access. > > > > We may able to move this id onto flags field but ...go step by step. > > > > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> > > --- > > include/linux/page_cgroup.h | 3 ++- > > mm/memcontrol.c | 40 +++++++++++++++++++++++++--------------- > > mm/page_cgroup.c | 2 +- > > 3 files changed, 28 insertions(+), 17 deletions(-) > > > > Index: mmotm-0719/include/linux/page_cgroup.h > > =================================================================== > > --- mmotm-0719.orig/include/linux/page_cgroup.h > > +++ mmotm-0719/include/linux/page_cgroup.h > > @@ -12,7 +12,8 @@ > > */ > > struct page_cgroup { > > unsigned long flags; > > - struct mem_cgroup *mem_cgroup; > > + unsigned short mem_cgroup; /* ID of assigned memory cgroup */ > > + unsigned short blk_cgroup; /* Not Used..but will be. */ > > So later I shall have to use virtually indexed arrays in blkio controller? > Or you are just using virtually indexed arrays for lookup speed and > I can continue to use css_lookup() and not worry about using virtually > indexed arrays. > yes. you can use css_lookup() even if it's slow.
> So the idea is that when a page is allocated, also store the blk_group > id and once that page is submitted for writeback, we should be able > to associate it to right blkio group? > blk_cgroup id can be attached whenever you wants. please overwrite page_cgroup->blk_cgroup when it's necessary. Did you read Ikeda's patch ? I myself doesn't have patches at this point. This is just for make a room for recording blkio-ID, which was requested for a year.
Hmm, but page-allocation-time doesn't sound very good for me.
Thanks. -Kame
| |