set the pointer to NULL after free the memory in free_percpu, so there is no need to set the pointer to NULL in the driver after calling free_percpu again. Signed-off-by: Tian Tao <tiantao6@hisilicon.com> --- mm/percpu.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/percpu.c b/mm/percpu.c index f53b89b..af944cc 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -2121,6 +2121,8 @@ void free_percpu(void __percpu *ptr) if (need_balance) pcpu_schedule_balance_work(); + + ptr = NULL; } EXPORT_SYMBOL_GPL(free_percpu); -- 2.7.4