Use cgroup id instead of css id. This is a preparation to kill css id.
Note, as memcg treat 0 as an invalid id, while cgroup id starts with 0,
we define memcg_id == cgroup_id + 1.
Signed-off-by: Li Zefan <lize...@huawei.com>
Acked-by: Michal Hocko <mho...@suse.cz>
---
mm/memcontrol.c | 34 ++++++++++++++++++++++++----------
1 file changed, 24 insertions(+), 10 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 626c426..62541f5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -512,6 +512,25 @@ static inline bool mem_cgroup_is_root(struct mem_cgroup
*memcg)
return (memcg == root_mem_cgroup);
}
+static inline unsigned short mem_cgroup_id(struct mem_cgroup *memcg)
+{
+ /*
+ * The ID of the root cgroup is 0, but memcg treat 0 as an
+ * invalid ID, so we return (cgroup_id + 1).
+ */
+ return memcg->css.cgroup->id + 1;
+}
+
+static inline struct mem_cgroup *mem_cgroup_from_id(unsigned short id)
+{
+ struct cgroup *cgrp;
+
+ cgrp = cgroup_from_id(&mem_cgroup_subsys, id - 1);
+ if (!cgrp)
+ return NULL;
+ return mem_cgroup_from_cont(cgrp);
+}
+
/* Writing them here to avoid exposing memcg's inner layout */
#if defined(CONFIG_INET) && defined(CONFIG_MEMCG_KMEM)
@@ -2821,15 +2840,10 @@ static void __mem_cgroup_cancel_local_charge(struct
mem_cgroup *memcg,
*/
static struct mem_cgroup *mem_cgroup_lookup(unsigned short id)
{
- struct cgroup_subsys_state *css;
-
/* ID 0 is unused ID */
if (!id)
return NULL;
- css = css_lookup(&mem_cgroup_subsys, id);
- if (!css)
- return NULL;
- return mem_cgroup_from_css(css);
+ return mem_cgroup_from_id(id);
}
struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page)
@@ -4328,7 +4342,7 @@ mem_cgroup_uncharge_swapcache(struct page *page,
swp_entry_t ent, bool swapout)
* css_get() was called in uncharge().
*/
if (do_swap_account && swapout && memcg)
- swap_cgroup_record(ent, css_id(&memcg->css));
+ swap_cgroup_record(ent, mem_cgroup_id(memcg));
}
#endif
@@ -4380,8 +4394,8 @@ static int mem_cgroup_move_swap_account(swp_entry_t entry,
{
unsigned short old_id, new_id;
- old_id = css_id(&from->css);
- new_id = css_id(&to->css);
+ old_id = mem_cgroup_id(from);
+ new_id = mem_cgroup_id(to);
if (swap_cgroup_cmpxchg(entry, old_id, new_id) == old_id) {
mem_cgroup_swap_statistics(from, false);
@@ -6542,7 +6556,7 @@ static enum mc_target_type get_mctgt_type(struct
vm_area_struct *vma,
}
/* There is a swap entry and a page doesn't exist or isn't charged */
if (ent.val && !ret &&
- css_id(&mc.from->css) == lookup_swap_cgroup_id(ent)) {
+ mem_cgroup_id(mc.from) == lookup_swap_cgroup_id(ent)) {
ret = MC_TARGET_SWAP;
if (target)
target->ent = ent;
--
1.8.0.2
--
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