[merged mm-stable] percpu-scoped-objcg-protection.patch removed from -mm tree

[merged mm-stable] percpu-scoped-objcg-protection.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: percpu: scoped objcg protection
has been removed from the -mm tree.  Its filename was
     percpu-scoped-objcg-protection.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Roman Gushchin <roman.gushchin@linux.dev>
Subject: percpu: scoped objcg protection
Date: Thu, 19 Oct 2023 15:53:45 -0700

Similar to slab and kmem, switch to a scope-based protection of the objcg
pointer to avoid.

Link: https://lkml.kernel.org/r/20231019225346.1822282-6-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin (Cruise) <roman.gushchin@linux.dev>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Acked-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/percpu.c |    8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

--- a/mm/percpu.c~percpu-scoped-objcg-protection
+++ a/mm/percpu.c
@@ -1628,14 +1628,12 @@ static bool pcpu_memcg_pre_alloc_hook(si
 	if (!memcg_kmem_online() || !(gfp & __GFP_ACCOUNT))
 		return true;
 
-	objcg = get_obj_cgroup_from_current();
+	objcg = current_obj_cgroup();
 	if (!objcg)
 		return true;
 
-	if (obj_cgroup_charge(objcg, gfp, pcpu_obj_full_size(size))) {
-		obj_cgroup_put(objcg);
+	if (obj_cgroup_charge(objcg, gfp, pcpu_obj_full_size(size)))
 		return false;
-	}
 
 	*objcgp = objcg;
 	return true;
@@ -1649,6 +1647,7 @@ static void pcpu_memcg_post_alloc_hook(s
 		return;
 
 	if (likely(chunk && chunk->obj_cgroups)) {
+		obj_cgroup_get(objcg);
 		chunk->obj_cgroups[off >> PCPU_MIN_ALLOC_SHIFT] = objcg;
 
 		rcu_read_lock();
@@ -1657,7 +1656,6 @@ static void pcpu_memcg_post_alloc_hook(s
 		rcu_read_unlock();
 	} else {
 		obj_cgroup_uncharge(objcg, pcpu_obj_full_size(size));
-		obj_cgroup_put(objcg);
 	}
 }
 
_

Patches currently in -mm which might be from roman.gushchin@linux.dev are