[PATCH] memcg: Remove the lockdep assert from __mod_objcg_mlstate().

[Sebastian Andrzej Siewior]

The assert was introduced in the commit cited below as an insurance that
the semantic is the same after the local_irq_save() has been removed and
the function has been made static.

The original requirement to disable interrupt was due the modification
of per-CPU counters which require interrupts to be disabled because the
counter update operation is not atomic and some of the counters are
updated from interrupt context.

All callers of __mod_objcg_mlstate() acquire a lock
(memcg_stock.stock_lock) which disables interrupts on !PREEMPT_RT and
the lockdep assert is satisfied. On PREEMPT_RT the interrupts are not
disabled and the assert triggers.

The safety of the counter update is already ensured by
VM_WARN_ON_IRQS_ENABLED() which is part of memcg_stats_lock() and does
not require yet another check.

Remove the lockdep assert from __mod_objcg_mlstate().

Fixes: 91882c1617c15 ("memcg: simple cleanup of stats update functions")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
 mm/memcontrol.c |    2 --
 1 file changed, 2 deletions(-)

--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3147,8 +3147,6 @@ static inline void __mod_objcg_mlstate(s
 	struct mem_cgroup *memcg;
 	struct lruvec *lruvec;
 
-	lockdep_assert_irqs_disabled();
-
 	rcu_read_lock();
 	memcg = obj_cgroup_memcg(objcg);
 	lruvec = mem_cgroup_lruvec(memcg, pgdat);