On Mon, Apr 20, 2009 at 06:38:15PM +0900, Ryo Tsuruta wrote: > Hi Andrea, > > > Implementing bio-cgroup functionality as pure infrastructure framework > > instead of a cgroup subsystem would remove all this oddity and > > complexity. > > > > For example, the actual functionality that I need for the io-throttle > > controller is just an interface to set and get the cgroup owner of a > > page. I think it should be the same also for other potential users of > > bio-cgroup. > > > > So, what about implementing the bio-cgroup functionality as cgroup "page > > tracking" infrastructure and provide the following interfaces: > > > > /* > > * Encode the cgrp->css.id in page_group->flags > > */ > > void set_cgroup_page_owner(struct page *page, struct cgroup *cgrp); > > > > /* > > * Returns the cgroup owner of a page, decoding the cgroup id from > > * page_cgroup->flags. > > */ > > struct cgroup *get_cgroup_page_owner(struct page *page); > > > > This also wouldn't increase the size of page_cgroup because we can > > encode the cgroup id in the unused bits of page_cgroup->flags, as > > originally suggested by Kame. > > > > And I think it could be used also by dm-ioband, even if it's not a > > cgroup-based subsystem... but I may be wrong. Ryo what's your opinion? > > I looked your page_cgroup patch in io-throttle v14, It can also be used > by dm-ioband. But I'd like to eliminate lock_page_cgroup() to minimize > overhead. I'll rearrange the bio-cgroup patch according to the functions. It would be great! Anyway, I don't think it's a trivial task to completely remove lock_page_cgroup(), especially if we decide to encode the ID in page_cgroup->flags. Thanks, -Andrea _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
