From 987eba66e0e6aa654d60881a14731a353ee0acb4 Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Thu, 20 Jan 2011 14:44:25 -0800 Subject: [PATCH] memcg: fix rmdir, force_empty with THP Now, when THP is enabled, memcg's rmdir() function is broken because move_account() for THP page is not supported. This will cause account leak or -EBUSY issue at rmdir(). This patch fixes the issue by supporting move_account() THP pages. Signed-off-by: KAMEZAWA Hiroyuki Cc: Daisuke Nishimura Cc: Balbir Singh Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 37 ++++++++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 11 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 7a94ef6..5b562b3 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2197,8 +2197,11 @@ void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail) */ static void __mem_cgroup_move_account(struct page_cgroup *pc, - struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge) + struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge, + int charge_size) { + int nr_pages = charge_size >> PAGE_SHIFT; + VM_BUG_ON(from == to); VM_BUG_ON(PageLRU(pc->page)); VM_BUG_ON(!page_is_cgroup_locked(pc)); @@ -2212,14 +2215,14 @@ static void __mem_cgroup_move_account(struct page_cgroup *pc, __this_cpu_inc(to->stat->count[MEM_CGROUP_STAT_FILE_MAPPED]); preempt_enable(); } - mem_cgroup_charge_statistics(from, PageCgroupCache(pc), -1); + mem_cgroup_charge_statistics(from, PageCgroupCache(pc), -nr_pages); if (uncharge) /* This is not "cancel", but cancel_charge does all we need. */ - mem_cgroup_cancel_charge(from, PAGE_SIZE); + mem_cgroup_cancel_charge(from, charge_size); /* caller should have done css_get */ pc->mem_cgroup = to; - mem_cgroup_charge_statistics(to, PageCgroupCache(pc), 1); + mem_cgroup_charge_statistics(to, PageCgroupCache(pc), nr_pages); /* * We charges against "to" which may not have any tasks. Then, "to" * can be under rmdir(). But in current implementation, caller of @@ -2234,15 +2237,19 @@ static void __mem_cgroup_move_account(struct page_cgroup *pc, * __mem_cgroup_move_account() */ static int mem_cgroup_move_account(struct page_cgroup *pc, - struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge) + struct mem_cgroup *from, struct mem_cgroup *to, + bool uncharge, int charge_size) { int ret = -EINVAL; unsigned long flags; + if ((charge_size > PAGE_SIZE) && !PageTransHuge(pc->page)) + return -EBUSY; + lock_page_cgroup(pc); if (PageCgroupUsed(pc) && pc->mem_cgroup == from) { move_lock_page_cgroup(pc, &flags); - __mem_cgroup_move_account(pc, from, to, uncharge); + __mem_cgroup_move_account(pc, from, to, uncharge, charge_size); move_unlock_page_cgroup(pc, &flags); ret = 0; } @@ -2267,6 +2274,8 @@ static int mem_cgroup_move_parent(struct page_cgroup *pc, struct cgroup *cg = child->css.cgroup; struct cgroup *pcg = cg->parent; struct mem_cgroup *parent; + int charge = PAGE_SIZE; + unsigned long flags; int ret; /* Is ROOT ? */ @@ -2278,17 +2287,23 @@ static int mem_cgroup_move_parent(struct page_cgroup *pc, goto out; if (isolate_lru_page(page)) goto put; + /* The page is isolated from LRU and we have no race with splitting */ + charge = PAGE_SIZE << compound_order(page); parent = mem_cgroup_from_cont(pcg); - ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false, - PAGE_SIZE); + ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false, charge); if (ret || !parent) goto put_back; - ret = mem_cgroup_move_account(pc, child, parent, true); + if (charge > PAGE_SIZE) + flags = compound_lock_irqsave(page); + + ret = mem_cgroup_move_account(pc, child, parent, true, charge); if (ret) - mem_cgroup_cancel_charge(parent, PAGE_SIZE); + mem_cgroup_cancel_charge(parent, charge); put_back: + if (charge > PAGE_SIZE) + compound_unlock_irqrestore(page, flags); putback_lru_page(page); put: put_page(page); @@ -4868,7 +4883,7 @@ retry: goto put; pc = lookup_page_cgroup(page); if (!mem_cgroup_move_account(pc, - mc.from, mc.to, false)) { + mc.from, mc.to, false, PAGE_SIZE)) { mc.precharge--; /* we uncharge from mc.from later. */ mc.moved_charge++; -- 2.7.4