Re: [PATCH v4 1/5] mm/memcg: Move mod_objcg_state() to memcontrol.c

From: Waiman Long
Date: Mon Apr 19 2021 - 12:18:53 EST


On 4/19/21 11:21 AM, Waiman Long wrote:
On 4/19/21 11:14 AM, Johannes Weiner wrote:
On Sun, Apr 18, 2021 at 08:00:28PM -0400, Waiman Long wrote:
The mod_objcg_state() function is moved from mm/slab.h to mm/memcontrol.c
so that further optimization can be done to it in later patches without
exposing unnecessary details to other mm components.

Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
---
  mm/memcontrol.c | 13 +++++++++++++
  mm/slab.h       | 16 ++--------------
  2 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e064ac0d850a..dc9032f28f2e 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3150,6 +3150,19 @@ void __memcg_kmem_uncharge_page(struct page *page, int order)
      css_put(&memcg->css);
  }
  +void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
+             enum node_stat_item idx, int nr)
+{
+    struct mem_cgroup *memcg;
+    struct lruvec *lruvec = NULL;
+
+    rcu_read_lock();
+    memcg = obj_cgroup_memcg(objcg);
+    lruvec = mem_cgroup_lruvec(memcg, pgdat);
+    mod_memcg_lruvec_state(lruvec, idx, nr);
+    rcu_read_unlock();
+}
It would be more naturally placed next to the others, e.g. below
__mod_lruvec_kmem_state().

But no deal breaker if there isn't another revision.

Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>

Yes, there will be another revision by rebasing patch series on the linux-next. I will move the function then.

OK, it turns out that mod_objcg_state() is only defined if CONFIG_MEMCG_KMEM. That was why I put it in the CONFIG_MEMCG_KMEM block with the other obj_stock functions. I think I will keep it there.

Thanks,
Longman