Re: [PATCH 0/2] vfio/iommufd: Prevent scheduler warnings when unmapping large regions

Jason Gunthorpe <[email protected]> Tue, 4 Aug 2026 12:50:06 -0300
Newsgroups org.kernel.vger.kvm
Message-ID <[email protected]>
On Fri, Jul 31, 2026 at 08:06:26AM -0700, Aaron Lewis wrote:

> > > > Given this is the same issue on both in the some place, I wonder if it
> > > > is better to try to get this series done:
> > > >
> > > > https://lore.kernel.org/linux-iommu/[email protected]/
> > > >
> > > > And put the cond sched inside the iova_to_phys_length() ?
> > > >
> > > > It would be fine to do things in steps, like add the
> > > > iova_to_phys_length() that just does the loops iommufd and vfio have
> > > > today with the additional cond sched inside which isn't such a big
> > > > task.
> > > >
> > > > Jason
> > >
> > > Ah, I think that is really what I wanted, but I proposed a solution to
> > > get feedback quicker.  I'll wait for that series to be merged and
> > > reaccess if a cond_resched() is still needed.  I'll follow up here
> > > once I've had a chance to run these tests again with it included.
> >
> > It seems kind of stalled, so IDK if you want to propose just a bit of
> > it that would be fine too
> >
> > Jason
> 
> Any idea what a minimum proposal would look like?  Looking at the
> series it all looks pretty relevant given the goal would be to have
> iova_to_phys_length() land.

I think if all you did was add the iova_to_phys_length() function in
the core code, implementing it as calling out to the drivers as is
today that would be a fine series

Jason