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

Andrew Morton <[email protected]> Mon, 13 Jul 2026 16:18:20 -0700

Newsgroups	org.freedesktop.lists.nouveau,org.freedesktop.lists.dri-devel,org.kernel.vger.linux-doc,org.kernel.vger.linux-hyperv,org.kernel.vger.linux-kernel,org.kernel.vger.linux-kselftest,org.kernel.vger.linux-rdma,org.kvack.linux-mm
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On Mon, 13 Jul 2026 09:59:17 -0700 Stanislav Kinsburskii <[email protected]> wrote:

> > > 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?
> > 
> > `timeout' and `jiffies' are both unsigned long.
> 
> Yeah, I’m sorry for the sloppy wording.
> 
> What I meant was: will "max(timeout - jiffies, 1UL)" correctly handle
> the case where jiffies < timeout?

That will return `timeout - jiffies': a smallish positive number.

I'm not sure what's intended here.  Perhaps the code should be
using time_after() or similar?