Hi Paul,
On 2020/9/19 1:59, Paul E. McKenney wrote:
> On Fri, Sep 18, 2020 at 07:44:24PM +0800, Hou Tao wrote:
>> When do locktorture for exclusive lock which doesn't have readlock
>> support, the following module parameters will be considered as valid:
>>
>> torture_type=mutex_lock nwriters_stress=0 nreaders_stress=1
>>
>> But locktorture will do nothing useful, so instead of permitting
>> these useless parameters, let's reject these parameters by returning
>> -EINVAL during module init.
>>
>> Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
>
> Much better, much easier for people a year from now to understand.
> Queued for v5.11, thank you!
>
> I did edit the commit log a bit as shown below, so please let me
> know if I messed anything up.
>
Thanks for your edit, it looks more clearer.
Regards,
Tao
> Thanx, Paul
>
> commit 4985c52e3b5237666265e59f56856f485ee36e71
> Author: Hou Tao <houtao1@xxxxxxxxxx>
> Date: Fri Sep 18 19:44:24 2020 +0800
>
> locktorture: Ignore nreaders_stress if no readlock support
>
> Exclusive locks do not have readlock support, which means that a
> locktorture run with the following module parameters will do nothing:
>
> torture_type=mutex_lock nwriters_stress=0 nreaders_stress=1
>
> This commit therefore rejects this combination for exclusive locks by
> returning -EINVAL during module init.
>
> Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
> Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
>
> diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
> index 316531d..046ea2d 100644
> --- a/kernel/locking/locktorture.c
> +++ b/kernel/locking/locktorture.c
> @@ -870,7 +870,8 @@ 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)) {
> pr_alert("lock-torture: must run at least one locking thread\n");
> firsterr = -EINVAL;
> goto unwind;
> .
>
