Hi Paul,
On 2020/9/18 0:58, Paul E. McKenney wrote:
> On Thu, Sep 17, 2020 at 09:59:09PM +0800, Hou Tao wrote:
>> To ensure there is always at least one locking thread.
>>
>> Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
>> ---
>> kernel/locking/locktorture.c | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
>> index 9cfa5e89cff7f..bebdf98e6cd78 100644
>> --- a/kernel/locking/locktorture.c
>> +++ b/kernel/locking/locktorture.c
>> @@ -868,7 +868,8 @@ static int __init lock_torture_init(void)
>> goto unwind;
>> }
>>
>> - if (nwriters_stress == 0 && nreaders_stress == 0) {
>> + if (nwriters_stress == 0 &&
>> + (!cxt.cur_ops->readlock || nreaders_stress == 0)) {
>
> You lost me on this one. How does it help to allow tests with zero
> writers on exclusive locks? Or am I missing something subtle here?
>
The purpose is to prohibit test with only readers on exclusive locks, not allow it.
So if the module parameters are "torture_type=mutex_lock nwriters_stress=0 nreaders_stress=3",
locktorture can fail early instead of continuing but doing nothing useful.
Regards,
Tao
> Thanx, Paul
>
>> pr_alert("lock-torture: must run at least one locking thread\n");
>> firsterr = -EINVAL;
>> goto unwind;
>> --
>> 2.25.0.4.g0ad7144999
>>
> .
>
