On Tue, Jul 14, 2026 at 01:13:38PM -0700, Stanislav Kinsburskii wrote:
> nouveau_range_fault() now uses hmm_range_fault_unlocked_timeout() for
> the HMM fault path. The timeout passed to that helper is meant to bound
> HMM's internal mmu-notifier retry loop, not the whole nouveau retry loop
> around mmu_interval_read_retry().
> 
> Pass the full relative HMM_RANGE_DEFAULT_TIMEOUT value to
> hmm_range_fault_unlocked_timeout() on each attempt, and retry from the
> nouveau-side mmu_interval_read_retry() check with a fresh HMM retry
> budget. This lets HMM continue when it has made progress, while still
> preserving a timeout for repeated notifier invalidation retries inside
> one HMM fault attempt.
> 
> This also removes the open-coded absolute deadline and remaining-time
> calculation from nouveau_range_fault().
> 

Sashiko is right. I'll need to do it differently.
There will be a v2 of this series.

Thanks,
Stanislav


> Signed-off-by: Stanislav Kinsburskii <[email protected]>
> ---
>  drivers/gpu/drm/nouveau/nouveau_svm.c |   30 ++++++++++--------------------
>  1 file changed, 10 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c 
> b/drivers/gpu/drm/nouveau/nouveau_svm.c
> index 4cfb6eb7c771..b1415c2e49fc 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_svm.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c
> @@ -655,8 +655,7 @@ static int nouveau_range_fault(struct nouveau_svmm *svmm,
>                              unsigned long hmm_flags,
>                              struct svm_notifier *notifier)
>  {
> -     unsigned long timeout =
> -             jiffies + msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
> +     unsigned long timeout = msecs_to_jiffies(HMM_RANGE_DEFAULT_TIMEOUT);
>       /* Have HMM fault pages within the fault window to the GPU. */
>       unsigned long hmm_pfns[1];
>       struct hmm_range range = {
> @@ -677,25 +676,16 @@ static int nouveau_range_fault(struct nouveau_svmm 
> *svmm,
>       range.start = notifier->notifier.interval_tree.start;
>       range.end = notifier->notifier.interval_tree.last + 1;
>  
> -     while (true) {
> -             if (time_after(jiffies, timeout)) {
> -                     ret = -EBUSY;
> -                     goto out;
> -             }
> -
> -             ret = hmm_range_fault_unlocked_timeout(&range,
> -                                                    max(timeout - jiffies,
> -                                                        1L));
> -             if (ret)
> -                     goto out;
> +again:
> +     ret = hmm_range_fault_unlocked_timeout(&range, timeout);
> +     if (ret)
> +             goto out;
>  
> -             mutex_lock(&svmm->mutex);
> -             if (mmu_interval_read_retry(range.notifier,
> -                                         range.notifier_seq)) {
> -                     mutex_unlock(&svmm->mutex);
> -                     continue;
> -             }
> -             break;
> +     mutex_lock(&svmm->mutex);
> +     if (mmu_interval_read_retry(range.notifier,
> +                                 range.notifier_seq)) {
> +             mutex_unlock(&svmm->mutex);
> +             goto again;
>       }
>  
>       nouveau_hmm_convert_pfn(drm, &range, args);
> 
> 

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