Messages in this thread Patch in this message | | | Date | Wed, 28 Oct 2020 20:10:54 +0100 | From | Sebastian Andrzej Siewior <> | Subject | [PATCH RT] mm/memcontrol: Disable preemption in __mod_memcg_lruvec_state() |
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The callers expect disabled preemption/interrupts while invoking __mod_memcg_lruvec_state(). This works mainline because a lock of some kind is acquired.
Use preempt_disable_rt() where per-CPU variables are accessed and a stable pointer is expected. This is also done in __mod_zone_page_state() for the same reason.
Cc: stable-rt@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- mm/memcontrol.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index f35ffe52cc4f8..09fa87f7a8119 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -829,6 +829,7 @@ void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, pn = container_of(lruvec, struct mem_cgroup_per_node, lruvec); memcg = pn->memcg; + preempt_disable_rt(); /* Update memcg */ __mod_memcg_state(memcg, idx, val); @@ -848,6 +849,7 @@ void __mod_memcg_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, x = 0; } __this_cpu_write(pn->lruvec_stat_cpu->count[idx], x); + preempt_enable_rt(); } /** -- 2.28.0
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