From 5564e88ba6fd2f6dcd83a592771810cd84b5ae80 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Wed, 23 Mar 2011 16:42:29 -0700 Subject: [PATCH] memcg: condense page_cgroup-to-page lookup points The per-cgroup LRU lists string up 'struct page_cgroup's. To get from those structures to the page they represent, a lookup is required. Currently, the lookup is done through a direct pointer in struct page_cgroup, so a lot of functions down the callchain do this lookup by themselves instead of receiving the page pointer from their callers. The next patch removes this pointer, however, and the lookup is no longer that straight-forward. In preparation for that, this patch only leaves the non-optional lookups when coming directly from the LRU list and passes the page down the stack. Signed-off-by: Johannes Weiner Acked-by: KAMEZAWA Hiroyuki Cc: Daisuke Nishimura Cc: Balbir Singh Cc: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memcontrol.c | 38 +++++++++++++++++++++++--------------- 1 file changed, 23 insertions(+), 15 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index e9d33dc151a5..e286e1603e4f 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1077,9 +1077,11 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, if (scan >= nr_to_scan) break; - page = pc->page; if (unlikely(!PageCgroupUsed(pc))) continue; + + page = pc->page; + if (unlikely(!PageLRU(page))) continue; @@ -2108,6 +2110,7 @@ struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) } static void __mem_cgroup_commit_charge(struct mem_cgroup *mem, + struct page *page, struct page_cgroup *pc, enum charge_type ctype, int page_size) @@ -2154,7 +2157,7 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *mem, * Insert ancestor (and ancestor's ancestors), to softlimit RB-tree. * if they exceeds softlimit. */ - memcg_check_events(mem, pc->page); + memcg_check_events(mem, page); } #ifdef CONFIG_TRANSPARENT_HUGEPAGE @@ -2201,6 +2204,7 @@ void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail) /** * mem_cgroup_move_account - move account of the page + * @page: the page * @pc: page_cgroup of the page. * @from: mem_cgroup which the page is moved from. * @to: mem_cgroup which the page is moved to. @from != @to. @@ -2216,7 +2220,7 @@ void mem_cgroup_split_huge_fixup(struct page *head, struct page *tail) * true, this function does "uncharge" from old cgroup, but it doesn't if * @uncharge is false, so a caller should do "uncharge". */ -static int mem_cgroup_move_account(struct page_cgroup *pc, +static int mem_cgroup_move_account(struct page *page, struct page_cgroup *pc, struct mem_cgroup *from, struct mem_cgroup *to, bool uncharge, int charge_size) { @@ -2225,7 +2229,7 @@ static int mem_cgroup_move_account(struct page_cgroup *pc, int ret; VM_BUG_ON(from == to); - VM_BUG_ON(PageLRU(pc->page)); + VM_BUG_ON(PageLRU(page)); /* * The page is isolated from LRU. So, collapse function * will not handle this page. But page splitting can happen. @@ -2233,7 +2237,7 @@ static int mem_cgroup_move_account(struct page_cgroup *pc, * hold it. */ ret = -EBUSY; - if (charge_size > PAGE_SIZE && !PageTransHuge(pc->page)) + if (charge_size > PAGE_SIZE && !PageTransHuge(page)) goto out; lock_page_cgroup(pc); @@ -2273,8 +2277,8 @@ unlock: /* * check events */ - memcg_check_events(to, pc->page); - memcg_check_events(from, pc->page); + memcg_check_events(to, page); + memcg_check_events(from, page); out: return ret; } @@ -2283,11 +2287,11 @@ out: * move charges to its parent. */ -static int mem_cgroup_move_parent(struct page_cgroup *pc, +static int mem_cgroup_move_parent(struct page *page, + struct page_cgroup *pc, struct mem_cgroup *child, gfp_t gfp_mask) { - struct page *page = pc->page; struct cgroup *cg = child->css.cgroup; struct cgroup *pcg = cg->parent; struct mem_cgroup *parent; @@ -2317,7 +2321,7 @@ static int mem_cgroup_move_parent(struct page_cgroup *pc, if (page_size > PAGE_SIZE) flags = compound_lock_irqsave(page); - ret = mem_cgroup_move_account(pc, child, parent, true, page_size); + ret = mem_cgroup_move_account(page, pc, child, parent, true, page_size); if (ret) mem_cgroup_cancel_charge(parent, page_size); @@ -2363,7 +2367,7 @@ static int mem_cgroup_charge_common(struct page *page, struct mm_struct *mm, if (ret || !mem) return ret; - __mem_cgroup_commit_charge(mem, pc, ctype, page_size); + __mem_cgroup_commit_charge(mem, page, pc, ctype, page_size); return 0; } @@ -2501,7 +2505,7 @@ __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr, cgroup_exclude_rmdir(&ptr->css); pc = lookup_page_cgroup(page); mem_cgroup_lru_del_before_commit_swapcache(page); - __mem_cgroup_commit_charge(ptr, pc, ctype, PAGE_SIZE); + __mem_cgroup_commit_charge(ptr, page, pc, ctype, PAGE_SIZE); mem_cgroup_lru_add_after_commit_swapcache(page); /* * Now swap is on-memory. This means this page may be @@ -2956,7 +2960,7 @@ int mem_cgroup_prepare_migration(struct page *page, ctype = MEM_CGROUP_CHARGE_TYPE_CACHE; else ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM; - __mem_cgroup_commit_charge(mem, pc, ctype, PAGE_SIZE); + __mem_cgroup_commit_charge(mem, page, pc, ctype, PAGE_SIZE); return ret; } @@ -3323,6 +3327,8 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *mem, loop += 256; busy = NULL; while (loop--) { + struct page *page; + ret = 0; spin_lock_irqsave(&zone->lru_lock, flags); if (list_empty(list)) { @@ -3338,7 +3344,9 @@ static int mem_cgroup_force_empty_list(struct mem_cgroup *mem, } spin_unlock_irqrestore(&zone->lru_lock, flags); - ret = mem_cgroup_move_parent(pc, mem, GFP_KERNEL); + page = pc->page; + + ret = mem_cgroup_move_parent(page, pc, mem, GFP_KERNEL); if (ret == -ENOMEM) break; @@ -4956,7 +4964,7 @@ retry: if (isolate_lru_page(page)) goto put; pc = lookup_page_cgroup(page); - if (!mem_cgroup_move_account(pc, + if (!mem_cgroup_move_account(page, pc, mc.from, mc.to, false, PAGE_SIZE)) { mc.precharge--; /* we uncharge from mc.from later. */ -- 2.20.1