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(). On successful migrate, we can
move the memcg information to new page's page_cgroup and mark the old
page's page_cgroup unused.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Hillf Danton <dhillf@xxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
---
include/linux/hugetlb_cgroup.h | 8 ++++++++
mm/hugetlb_cgroup.c | 30 ++++++++++++++++++++++++++++++
mm/migrate.c | 5 +++++
3 files changed, 43 insertions(+)
diff --git a/include/linux/hugetlb_cgroup.h b/include/linux/hugetlb_cgroup.h
index fbf8c5f..387cbd6 100644
--- a/include/linux/hugetlb_cgroup.h
+++ b/include/linux/hugetlb_cgroup.h
@@ -43,6 +43,8 @@ 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 bool hugetlb_cgroup_disabled(void)
{
@@ -81,5 +83,11 @@ 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 49a3f20..f99007b 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -401,6 +401,36 @@ int __init hugetlb_cgroup_file_init(int idx)
return 0;
}
+void hugetlb_cgroup_migrate(struct page *oldhpage, struct page *newhpage)
+{
+ struct cgroup *cg;
+ struct page_cgroup *pc;
+ struct hugetlb_cgroup *h_cg;
+
+ VM_BUG_ON(!PageHuge(oldhpage));
+
+ if (hugetlb_cgroup_disabled())
+ return;
+
+ pc = lookup_page_cgroup(oldhpage);
+ lock_page_cgroup(pc);
+ cg = pc->cgroup;
+ h_cg = hugetlb_cgroup_from_cgroup(cg);
+ pc->cgroup = root_h_cgroup->css.cgroup;
+ ClearPageCgroupUsed(pc);
+ cgroup_exclude_rmdir(&h_cg->css);
+ unlock_page_cgroup(pc);
+
+ /* move the h_cg details to new cgroup */
+ pc = lookup_page_cgroup(newhpage);
+ lock_page_cgroup(pc);
+ pc->cgroup = cg;
+ SetPageCgroupUsed(pc);
+ unlock_page_cgroup(pc);
+ cgroup_release_and_wakeup_rmdir(&h_cg->css);
+ return;
+}
+
struct cgroup_subsys hugetlb_subsys = {
.name = "hugetlb",
.create = hugetlb_cgroup_create,
diff --git a/mm/migrate.c b/mm/migrate.c
index 927254c..22f414f 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -33,6 +33,7 @@
#include <linux/memcontrol.h>
#include <linux/syscalls.h>
#include <linux/hugetlb.h>
+#include <linux/hugetlb_cgroup.h>
#include <linux/gfp.h>
#include <asm/tlbflush.h>
@@ -928,6 +929,10 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
if (anon_vma)
put_anon_vma(anon_vma);
+
+ if (!rc)
+ hugetlb_cgroup_migrate(hpage, new_hpage);
+
unlock_page(hpage);
out:
put_page(new_hpage);
--
1.7.10
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