On 2024/9/2 20:16, Mathieu Desnoyers wrote:
> On 2024-09-02 07:06, Jinjie Ruan wrote:
>> sizeof(unsigned long) * 8 is the number of bits in an unsigned long
>> variable, replace it with BITS_PER_LONG macro to make it simpler.
>
> An alternative would be:
>
> if (rcu_fanout_leaf < 2 || sizeof_field(struct rcu_node, qsmask) *
> CHAR_BIT) {
>
> which would then tie the check to validated member type. But it's
> slightly more verbose, so it's up to the maintainer really.
Yes, it reflects the original purpose but it is too long.
>
> Thanks,
>
> Mathieu
>
>>
>> Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
>> ---
>> kernel/rcu/tree.c | 3 +--
>> 1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
>> index a60616e69b66..b48864df415c 100644
>> --- a/kernel/rcu/tree.c
>> +++ b/kernel/rcu/tree.c
>> @@ -5579,8 +5579,7 @@ void rcu_init_geometry(void)
>> * Complain and fall back to the compile-time values if this
>> * limit is exceeded.
>> */
>> - if (rcu_fanout_leaf < 2 ||
>> - rcu_fanout_leaf > sizeof(unsigned long) * 8) {
>> + if (rcu_fanout_leaf < 2 || rcu_fanout_leaf > BITS_PER_LONG) {
>> rcu_fanout_leaf = RCU_FANOUT_LEAF;
>> WARN_ON(1);
>> return;
>
