Re: [patch 2/4] io controller: biocgroup implementation

[Vivek Goyal <vgoyal@redhat.com>]

On Fri, Nov 07, 2008 at 11:50:30AM +0900, KAMEZAWA Hiroyuki wrote:
> On Thu, 06 Nov 2008 10:30:24 -0500
> vgoyal@redhat.com wrote:
> 
> > 
> > o biocgroup functionality.
> > o Implemented new controller "bio"
> > o Most of it picked from dm-ioband biocgroup implementation patches.
> > 
> page_cgroup implementation is changed and most of this patch needs rework.
> please see the latest one. (I think most of new characteristics are useful
> for you.)
> 

Sure I will have a look.

> One comment from me is
> ==
> > +struct page_cgroup {
> > +	struct list_head lru;		/* per cgroup LRU list */
> > +	struct page *page;
> > +	struct mem_cgroup *mem_cgroup;
> > +	int flags;
> > +#ifdef CONFIG_CGROUP_BIO
> > +	struct list_head blist;		/* for bio_cgroup page list */
> > +	struct bio_cgroup *bio_cgroup;
> > +#endif
> > +};
> ==
> 
> this blist is too bad. please keep this object small...
> 

This is just another connecting element so that page_cgroup can be on another
list also. It is useful in making sure that IO on all the pages of a bio
group has completed beofer that bio cgroup is deleted.

> Maybe dm-ioband people will post his own new one. just making use of it is an idea.

Sure, I will have a look when dm-ioband people post new version of patch
and how they have optimized it further.

Thanks
Vivek