Re: [PATCH 3/4] locking/ww_mutex: Treat ww_mutex_lock() like a trylock

Boqun Feng
2021-03-18T06:37:48Z

On Wed, Mar 17, 2021 at 10:54:17PM -0400, Waiman Long wrote:
> On 3/17/21 10:24 PM, Boqun Feng wrote:
> > Hi Waiman,
> >
> > Just a question out of curiosity: how does this problem hide so long?
> > ;-) Because IIUC, both locktorture and ww_mutex_lock have been there for
> > a while, so why didn't we spot this earlier?
> >
> > I ask just to make sure we don't introduce the problem because of some
> > subtle problems in lock(dep).
> >
> You have to explicitly specify ww_mutex in the locktorture module parameter
> to run the test. ww_mutex is usually not the intended target of testing as
> there aren't that many places that use it. Even if someone run it, it
> probably is not on a debug kernel.
>
> Our QA people try to run locktorture on ww_mutex and discover that.
>

Got it. Thanks ;-)

Regards,
Boqun

> Cheers,
> Longman
>