RE: [RFC 01/20] iommu/iommufd: Add /dev/iommu core

[Liu, Yi L]

> From: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Sent: Friday, October 15, 2021 7:18 PM
> 
> On Fri, Oct 15, 2021 at 09:18:06AM +0000, Liu, Yi L wrote:
> 
> > >   Acquire from the xarray is
> > >    rcu_lock()
> > >    ioas = xa_load()
> > >    if (ioas)
> > >       if (down_read_trylock(&ioas->destroying_lock))
> >
> > all good suggestions, will refine accordingly. Here destroying_lock is a
> > rw_semaphore. right? Since down_read_trylock() accepts a rwsem.
> 
> Yes, you probably need a sleeping lock

got it. thanks,

Regards,
Yi Liu