[folded-merged] mm-memcontrol-decouple-reference-counting-from-page-accounting-fix.patch removed from -mm tree

[folded-merged] mm-memcontrol-decouple-reference-counting-from-page-accounting-fix.patch removed from -mm tree

[akpm]

The patch titled
     Subject: mm: memcontrol: decouple reference counting from page accounting fix
has been removed from the -mm tree.  Its filename was
     mm-memcontrol-decouple-reference-counting-from-page-accounting-fix.patch

This patch was dropped because it was folded into mm-memcontrol-decouple-reference-counting-from-page-accounting.patch

------------------------------------------------------
From: Hugh Dickins <hughd@google.com>
Subject: mm: memcontrol: decouple reference counting from page accounting fix

Moving tasks between mem cgroups with memory.move_charge_at_immigrate 3,
while swapping, crashes soon on mmotm (and so presumably on linux-next):
for example, spinlock found corrupted when lock_page_memcg() is called. 
It's as if the mem cgroup structures have been freed too early.

Stab in the dark: what if all the accounting is right, except that the
css_put_many() in __mem_cgroup_clear_mc() is now (worse than) redundant? 
Removing it fixes the crashes, but that's hardly surprising; and stats
temporarily hacked into mem_cgroup_css_alloc() and mem_cgroup_css_free()
showed that mem cgroups were not being leaked with this change.

Note: this removes the last call to css_put_many() from the tree; and
mm-memcg-slab-use-a-single-set-of-kmem_caches-for-all-accounted-allocations.patch
removes the last call to css_get_many(): now that their last references
have gone, I expect them soon to be freed from include/linux/cgroup.h.

Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2007302011450.2347@eggly.anvils
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/memcontrol.c |    2 --
 1 file changed, 2 deletions(-)

--- a/mm/memcontrol.c~mm-memcontrol-decouple-reference-counting-from-page-accounting-fix
+++ a/mm/memcontrol.c
@@ -5680,8 +5680,6 @@ static void __mem_cgroup_clear_mc(void)
 		if (!mem_cgroup_is_root(mc.to))
 			page_counter_uncharge(&mc.to->memory, mc.moved_swap);
 
-		css_put_many(&mc.to->css, mc.moved_swap);
-
 		mc.moved_swap = 0;
 	}
 	memcg_oom_recover(from);
_

Patches currently in -mm which might be from hughd@google.com are

mm-memcontrol-decouple-reference-counting-from-page-accounting.patch
khugepaged-collapse_pte_mapped_thp-flush-the-right-range.patch
khugepaged-collapse_pte_mapped_thp-protect-the-pmd-lock.patch
khugepaged-retract_page_tables-remember-to-test-exit.patch
khugepaged-khugepaged_test_exit-check-mmget_still_valid.patch