Kamezawa Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> writes: > (2012/06/09 18:00), Aneesh Kumar K.V wrote: >> From: "Aneesh Kumar K.V"<aneesh.kumar@xxxxxxxxxxxxxxxxxx> >> >> With HugeTLB pages, hugetlb cgroup is uncharged in compound page destructor. Since >> we are holding a hugepage reference, we can be sure that old page won't >> get uncharged till the last put_page(). >> >> Signed-off-by: Aneesh Kumar K.V<aneesh.kumar@xxxxxxxxxxxxxxxxxx> > > one comment. > >> --- >> include/linux/hugetlb_cgroup.h | 8 ++++++++ >> mm/hugetlb_cgroup.c | 21 +++++++++++++++++++++ >> mm/migrate.c | 5 +++++ >> 3 files changed, 34 insertions(+) >> >> diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h >> index ba4836f..b64d067 100644 >> --- a/include/linux/hugetlb_cgroup.h >> +++ b/include/linux/hugetlb_cgroup.h >> @@ -63,6 +63,8 @@ extern void hugetlb_cgroup_uncharge_page(int idx, unsigned long nr_pages, >> extern void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages, >> struct hugetlb_cgroup *h_cg); >> extern int hugetlb_cgroup_file_init(int idx) __init; >> +extern void hugetlb_cgroup_migrate(struct page *oldhpage, >> + struct page *newhpage); >> #else >> static inline struct hugetlb_cgroup *hugetlb_cgroup_from_page(struct page *page) >> { >> @@ -112,5 +114,11 @@ static inline int __init hugetlb_cgroup_file_init(int idx) >> { >> return 0; >> } >> + >> +static inline void hugetlb_cgroup_migrate(struct page *oldhpage, >> + struct page *newhpage) >> +{ >> + return; >> +} >> #endif /* CONFIG_MEM_RES_CTLR_HUGETLB */ >> #endif >> diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c >> index c2b7b8e..2d384fe 100644 >> --- a/mm/hugetlb_cgroup.c >> +++ b/mm/hugetlb_cgroup.c >> @@ -394,6 +394,27 @@ int __init hugetlb_cgroup_file_init(int idx) >> return 0; >> } >> >> +void hugetlb_cgroup_migrate(struct page *oldhpage, struct page *newhpage) >> +{ >> + struct hugetlb_cgroup *h_cg; >> + >> + VM_BUG_ON(!PageHuge(oldhpage)); >> + >> + if (hugetlb_cgroup_disabled()) >> + return; >> + >> + spin_lock(&hugetlb_lock); >> + h_cg = hugetlb_cgroup_from_page(oldhpage); >> + set_hugetlb_cgroup(oldhpage, NULL); >> + cgroup_exclude_rmdir(&h_cg->css); >> + >> + /* move the h_cg details to new cgroup */ >> + set_hugetlb_cgroup(newhpage, h_cg); >> + spin_unlock(&hugetlb_lock); >> + cgroup_release_and_wakeup_rmdir(&h_cg->css); >> + return; > > > Why do you need cgroup_exclude/release rmdir here ? you holds hugetlb_lock() > and charges will not be empty, here. > But even without empty charge, we can still remove the cgroup right ? ie if we don't have any task but some charge in the cgroup because of shared mmap in hugetlbfs. -aneesh -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html