From: KAMEZAWA Hiroyuki Date: Tue, 29 May 2012 22:07:03 +0000 (-0700) Subject: memcg: use res_counter_uncharge_until() in move_parent() X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=d01dd17f1067ca50dbb9d1d3400d33221ce339e7;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git memcg: use res_counter_uncharge_until() in move_parent() By using res_counter_uncharge_until(), we can avoid race and unnecessary charging. Signed-off-by: KAMEZAWA Hiroyuki Cc: Aneesh Kumar K.V Cc: Michal Hocko Cc: Johannes Weiner Cc: Frederic Weisbecker Cc: Ying Han Cc: Glauber Costa Reviewed-by: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 9d1764630dff..1262a8bc402b 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2422,6 +2422,24 @@ static void __mem_cgroup_cancel_charge(struct mem_cgroup *memcg, } } +/* + * Cancel chrages in this cgroup....doesn't propagate to parent cgroup. + * This is useful when moving usage to parent cgroup. + */ +static void __mem_cgroup_cancel_local_charge(struct mem_cgroup *memcg, + unsigned int nr_pages) +{ + unsigned long bytes = nr_pages * PAGE_SIZE; + + if (mem_cgroup_is_root(memcg)) + return; + + res_counter_uncharge_until(&memcg->res, memcg->res.parent, bytes); + if (do_swap_account) + res_counter_uncharge_until(&memcg->memsw, + memcg->memsw.parent, bytes); +} + /* * A helper function to get mem_cgroup from ID. must be called under * rcu_read_lock(). The caller must check css_is_removed() or some if @@ -2680,16 +2698,28 @@ static int mem_cgroup_move_parent(struct page *page, nr_pages = hpage_nr_pages(page); parent = mem_cgroup_from_cont(pcg); - ret = __mem_cgroup_try_charge(NULL, gfp_mask, nr_pages, &parent, false); - if (ret) - goto put_back; + if (!parent->use_hierarchy) { + ret = __mem_cgroup_try_charge(NULL, + gfp_mask, nr_pages, &parent, false); + if (ret) + goto put_back; + } if (nr_pages > 1) flags = compound_lock_irqsave(page); - ret = mem_cgroup_move_account(page, nr_pages, pc, child, parent, true); - if (ret) - __mem_cgroup_cancel_charge(parent, nr_pages); + if (parent->use_hierarchy) { + ret = mem_cgroup_move_account(page, nr_pages, + pc, child, parent, false); + if (!ret) + __mem_cgroup_cancel_local_charge(child, nr_pages); + } else { + ret = mem_cgroup_move_account(page, nr_pages, + pc, child, parent, true); + + if (ret) + __mem_cgroup_cancel_charge(parent, nr_pages); + } if (nr_pages > 1) compound_unlock_irqrestore(page, flags);