Re: [PATCH v8 5/8] drm/nouveau: Use hmm_range_fault_unlocked_timeout() for SVM faults

Stanislav Kinsburskii <[email protected]> Fri, 10 Jul 2026 20:16:35 -0700

Newsgroups	org.kernel.vger.linux-hyperv,org.freedesktop.lists.dri-devel,org.freedesktop.lists.nouveau,org.kernel.vger.linux-doc,org.kernel.vger.linux-kernel,org.kernel.vger.linux-kselftest,org.kernel.vger.linux-rdma,org.kvack.linux-mm
Message-ID	<alG1k3JsoywE2CBM@skinsburskii>

On Fri, Jul 10, 2026 at 03:12:22PM -0700, Andrew Morton wrote:
> On Fri, 10 Jul 2026 14:26:58 -0700 Stanislav Kinsburskii <[email protected]> wrote:
> 
> > @@ -683,15 +683,11 @@ static int nouveau_range_fault(struct nouveau_svmm *svmm,
> >  			goto out;
> >  		}
> >  
> > -		range.notifier_seq = mmu_interval_read_begin(range.notifier);
> > -		mmap_read_lock(mm);
> > -		ret = hmm_range_fault(&range);
> > -		mmap_read_unlock(mm);
> > -		if (ret) {
> > -			if (ret == -EBUSY)
> > -				continue;
> > +		ret = hmm_range_fault_unlocked_timeout(&range,
> > +						       max(timeout - jiffies,
> > +							   1L));
> 
> "1UL" here?  I'd have expected min() to warn, as it likes to do.

I'm not sure... The "timeout - jiffies" can become negative.
Won't 1UL convert both of them to "UL" and thus make the comparison
overflow?

Thanks,
Stanislav