Messages in this thread Patch in this message | | | Date | Thu, 21 Jul 2011 14:42:23 +0200 | From | Michal Hocko <> | Subject | Re: [PATCH 3/4] memcg: get rid of percpu_charge_mutex lock |
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On Thu 21-07-11 13:47:04, Michal Hocko wrote: > On Thu 21-07-11 19:30:51, KAMEZAWA Hiroyuki wrote: > > On Thu, 21 Jul 2011 09:58:24 +0200 > > Michal Hocko <mhocko@suse.cz> wrote: [...] > > > --- a/mm/memcontrol.c > > > +++ b/mm/memcontrol.c > > > @@ -2166,7 +2165,8 @@ static void drain_all_stock(struct mem_cgroup *root_mem, bool sync) > > > > > > for_each_online_cpu(cpu) { > > > struct memcg_stock_pcp *stock = &per_cpu(memcg_stock, cpu); > > > - if (test_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) > > > + if (root_mem == stock->cached && > > > + test_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) > > > flush_work(&stock->work); > > > > Doesn't this new check handle hierarchy ? > > css_is_ancestor() will be required if you do this check. > > Yes you are right. Will fix it. I will add a helper for the check.
Here is the patch with the helper. The above will then read if (mem_cgroup_same_or_subtree(root_mem, stock->cached))
--- From b963a9f4dac61044daac49700f84b7819d7c2f53 Mon Sep 17 00:00:00 2001 From: Michal Hocko <mhocko@suse.cz> Date: Thu, 21 Jul 2011 13:54:13 +0200 Subject: [PATCH] memcg: add mem_cgroup_same_or_subtree helper
We are checking whether a given two groups are same or at least in the same subtree of a hierarchy at several places. Let's make a helper for it to make code easier to read.
Signed-off-by: Michal Hocko <mhocko@suse.cz> --- mm/memcontrol.c | 29 ++++++++++++++++++----------- 1 files changed, 18 insertions(+), 11 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 8180cd9..8dbb9d6 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1046,6 +1046,21 @@ void mem_cgroup_move_lists(struct page *page, mem_cgroup_add_lru_list(page, to); } +/* + * Checks whether given mem is same or in the root_mem's + * hierarchy subtree + */ +static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_mem, + struct mem_cgroup *mem) +{ + if (root_mem != mem) { + return (root_mem->use_hierarchy && + css_is_ancestor(&mem->css, &root_mem->css)); + } + + return true; +} + int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) { int ret; @@ -1065,10 +1080,7 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem) * enabled in "curr" and "curr" is a child of "mem" in *cgroup* * hierarchy(even if use_hierarchy is disabled in "mem"). */ - if (mem->use_hierarchy) - ret = css_is_ancestor(&curr->css, &mem->css); - else - ret = (curr == mem); + ret = mem_cgroup_same_or_subtree(mem, curr); css_put(&curr->css); return ret; } @@ -2150,13 +2162,8 @@ static void drain_all_stock(struct mem_cgroup *root_mem, bool sync) mem = stock->cached; if (!mem || !stock->nr_pages) continue; - if (mem != root_mem) { - if (!root_mem->use_hierarchy) - continue; - /* check whether "mem" is under tree of "root_mem" */ - if (!css_is_ancestor(&mem->css, &root_mem->css)) - continue; - } + if (!mem_cgroup_same_or_subtree(root_mem, mem)) + continue; if (!test_and_set_bit(FLUSHING_CACHED_CHARGE, &stock->flags)) schedule_work_on(cpu, &stock->work); } -- 1.7.5.4
-- Michal Hocko SUSE Labs SUSE LINUX s.r.o. Lihovarska 1060/12 190 00 Praha 9 Czech Republic
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