On Wed, 23 Feb 2011 09:59:11 +0100 Andrea Righi <arighi@xxxxxxxxxxx> wrote: > > > > I wonder I can make pc->mem_cgroup to be pc->memid(16bit), then, > > == > > static inline struct mem_cgroup *get_memcg_from_pc(struct page_cgroup *pc) > > { > > struct cgroup_subsys_state *css = css_lookup(&mem_cgroup_subsys, pc->memid); > > return container_of(css, struct mem_cgroup, css); > > } > > == > > Overhead will be seen at updating file statistics and LRU management. > > > > But, hmm, can't you do that tracking without page_cgroup ? > > Because the number of dirty/writeback pages are far smaller than total pages, > > chasing I/O with dynamic structure is not very bad.. > > > > prepareing [pfn -> blkio] record table and move that information to struct bio > > in dynamic way is very difficult ? > > This would be ok for dirty pages, but consider that we're also tracking > anonymous pages. So, if we want to control the swap IO we actually need > to save this information for a lot of pages and at the end I think we'll > basically duplicate the page_cgroup code. > swap io is always started with bio and the task/mm_struct. So, if we can record information in bio, no page tracking is required. You can record information to bio just by reading mm->owner. Thanks, -Kame _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers