Re: PREEMPT_RT vs i915

From	Ville Syrjälä <ville.syrjala@linux.intel.com>
Newsgroups	linux.debian.kernel
Subject	Re: PREEMPT_RT vs i915
Date	2025-07-09 22:40 +0200
Message-ID	<L6JK9-grwF-1@gated-at.bofh.it> (permalink)
References	<L6mkx-gbhA-1@gated-at.bofh.it> <L6Hfj-gpKT-1@gated-at.bofh.it> <L6Jh7-grlT-9@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Wed, Jul 09, 2025 at 09:44:43PM +0200, Sebastian Andrzej Siewior wrote:
> On 2025-07-09 20:30:26 [+0300], Ville Syrjälä wrote:
> > > 
> > > It seems like the critical uncore lock is currently held in a lot of
> > > places and potentially for a long time.
> > 
> > It shouldn't be held for that long. I think it should just be
> > a raw spinlock.
> 
> What about I resubmit the series and we look again? I don't think the
> lock should be made raw just to be done with it.

Until someone actually does the work to confirm the thing is working
reliably there's no point in posting anything.

And IIRC the other remaining problem with RT was the spinlocks used
inside tracepoints (which is uncore lock, and probably some vblank
locks). So that too needs some kind of solution because it's going to
very hard to debug the timing sensitive parts without the tracepoints.

-- 
Ville Syrjälä
Intel

Thread

PREEMPT_RT vs i915 Ben Hutchings <ben@decadent.org.uk> - 2025-07-08 21:40 +0200
  Re: PREEMPT_RT vs i915 Ville Syrjälä <ville.syrjala@linux.intel.com> - 2025-07-09 20:00 +0200
    Re: PREEMPT_RT vs i915 Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2025-07-09 22:10 +0200
      Re: PREEMPT_RT vs i915 Ville Syrjälä <ville.syrjala@linux.intel.com> - 2025-07-09 22:40 +0200
        Re: PREEMPT_RT vs i915 Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2025-07-10 08:50 +0200
        Re: PREEMPT_RT vs i915 Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2025-07-10 09:00 +0200
          Re: PREEMPT_RT vs i915 Ville Syrjälä <ville.syrjala@linux.intel.com> - 2025-07-10 17:30 +0200
            Re: PREEMPT_RT vs i915 Sebastian Andrzej Siewior <bigeasy@linutronix.de> - 2025-07-10 17:40 +0200
              Re: PREEMPT_RT vs i915 Maarten Lankhorst <maarten.lankhorst@linux.intel.com> - 2025-07-11 15:10 +0200
        Re: PREEMPT_RT vs i915 Ville Syrjälä <ville.syrjala@linux.intel.com> - 2025-07-10 17:40 +0200
          Re: PREEMPT_RT vs i915 Ville Syrjälä <ville.syrjala@linux.intel.com> - 2025-07-10 20:40 +0200
        Re: PREEMPT_RT vs i915 Ville Syrjälä <ville.syrjala@linux.intel.com> - 2025-07-10 18:10 +0200

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