Messages in this thread | | | Date | Thu, 21 Aug 2008 17:34:42 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [RFC][PATCH -mm 0/7] memcg: lockless page_cgroup v1 |
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On Wed, 20 Aug 2008 20:00:06 +0900 KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote: > > Known problem: force_emtpy is broken...so rmdir will struck into nightmare. > > It's because of patch 2/7. > > will be fixed in the next version. > > > This is a new routine for force_empty. Assumes init_mem_cgroup has no limit. (lockless page_cgroup is also applied.)
I think this routine is enough generic to be enhanced for hierarchy in future. I think move_account() routine can be used for other purpose. (for example, move_task.)
== int mem_cgroup_move_account(struct page *page, struct page_cgroup *pc, struct mem_cgroup *from, struct mem_cgroup *to) { struct mem_cgroup_per_zone *from_mz, *to_mz; int nid, zid; int ret = 1;
VM_BUG_ON(to->no_limit == 0); VM_BUG_ON(!irqs_disabled());
nid = page_to_nid(page); zid = page_zonenum(page); from_mz = mem_cgroup_zoneinfo(from, nid, zid); to_mz = mem_cgroup_zoneinfo(to, nid, zid);
if (res_counter_charge(&to->res, PAGE_SIZE)) { /* Now, we assume no_limit...no failure here. */ return ret; }
if (spin_trylock(&to_mz->lru_lock)) { __mem_cgroup_remove_list(from_mz, pc); css_put(&from->css); res_counter_uncharge(&from->res, PAGE_SIZE); pc->mem_cgroup = to; css_get(&to->css); __mem_cgroup_add_list(to_mz, pc); ret = 0; spin_unlock(&to_mz->lru_lock); } else { res_counter_uncharge(&to->res, PAGE_SIZE); }
return ret; } /* * This routine moves all account to root cgroup. */ static void mem_cgroup_force_empty_list(struct mem_cgroup *mem, struct mem_cgroup_per_zone *mz, enum lru_list lru) { struct page_cgroup *pc; unsigned long flags; struct list_head *list; int drain = 0;
list = &mz->lists[lru];
spin_lock_irqsave(&mz->lru_lock, flags); while (!list_empty(list)) { pc = list_entry(list->prev, struct page_cgroup, lru); if (PcgObsolete(pc)) { list_move(&pc->lru, list); /* This page_cgroup may remain on this list until we drain it. */ if (drain++ > MEMCG_LRU_THRESH/2) { spin_unlock_irqrestore(&mz->lru_lock, flags); mem_cgroup_all_force_drain(); yield(); drain = 0; spin_lock_irqsave(&mz->lru_lock, flags); } continue; } if (mem_cgroup_move_account(page, pc->page, mem, &init_mem_cgroup)) { /* some confliction */ list_move(&pc->lru, list); spin_unlock_irqrestore(&mz->lru_lock, flags); yield(); spin_lock_irqsave(&mz->lru_lock, flags); } if (atomic_read(&mem->css.cgroup->count) > 0) break; } spin_unlock_irqrestore(&mz->lru_lock, flags); } ==
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