mbox series

[00/10] drm/i915: PREEMPT_RT related fixups.

Message ID 20240405142737.920626-1-bigeasy@linutronix.de (mailing list archive)
Headers show
Series drm/i915: PREEMPT_RT related fixups. | expand

Message

Sebastian Andrzej Siewior April 5, 2024, 2:18 p.m. UTC 
Hi,

The following patches are from the PREEMPT_RT queue.  It is mostly about
disabling interrupts/preemption which leads to problems. Unfortunately
DRM_I915_LOW_LEVEL_TRACEPOINTS had to be disabled because it acquires locks
from within trace points. Making the lock a raw_spinlock_t led to higher
latencies during video playback
  https://lore.kernel.org/all/20211006164628.s2mtsdd2jdbfyf7g@linutronix.de/

and I'm not sure if I hit the worse case here.
I tested it on a SandyBridge with built-in i915 by using X, OpenGL and
playing videos without noticing any warnings. However, some code paths
were not entered.
I carry them for some time now and most issues were reported by other
people and they reported that things work for them since.

Sebastian

Comments

Sebastian Andrzej Siewior June 5, 2024, 10:01 a.m. UTC | #1 
On 2024-04-05 16:18:18 [+0200], To intel-gfx@lists.freedesktop.org wrote:
Hi,

> The following patches are from the PREEMPT_RT queue.  It is mostly about
> disabling interrupts/preemption which leads to problems. Unfortunately
…

Could I please get some feedback? I didn't receive anything but
automated mails from bots and I can't tell if this is a problem or not.

As of -rc2 I noticed that I can drop
	[PATCH 06/10] drm/i915/gt: Queue and wait for the irq_work item.

from the series.

Sebastian
Tvrtko Ursulin June 11, 2024, 1:06 p.m. UTC | #2 
Hi Sebastian,

On 05/06/2024 11:01, Sebastian Andrzej Siewior wrote:
> On 2024-04-05 16:18:18 [+0200], To intel-gfx@lists.freedesktop.org wrote:
> Hi,
> 
>> The following patches are from the PREEMPT_RT queue.  It is mostly about
>> disabling interrupts/preemption which leads to problems. Unfortunately
> …
> 
> Could I please get some feedback? I didn't receive anything but
> automated mails from bots and I can't tell if this is a problem or not.
> 
> As of -rc2 I noticed that I can drop
> 	[PATCH 06/10] drm/i915/gt: Queue and wait for the irq_work item.
> 
> from the series.

Previous CI results have unfortunately expired by now. I have tried 
re-queuing it but it also does not apply any longer so I'm afraid you 
will have to respin before anyone can see the results.

And this is not to say that I can promise someone will look at it or 
when. Maybe Jani you could ask for volunteers regarding the display 
related patches (head of the series) and Rodrigo you about the GuC 
change in 9/10?

Regards,

Tvrtko
Sebastian Andrzej Siewior June 11, 2024, 3:14 p.m. UTC | #3 
On 2024-06-11 14:06:00 [+0100], Tvrtko Ursulin wrote:
> 
> Hi Sebastian,
Hi Tvrtko,

> Previous CI results have unfortunately expired by now. I have tried
> re-queuing it but it also does not apply any longer so I'm afraid you will
> have to respin before anyone can see the results.

No worries, I rebased it for latest RT release, I can respost them.

> And this is not to say that I can promise someone will look at it or when.
> Maybe Jani you could ask for volunteers regarding the display related
> patches (head of the series) and Rodrigo you about the GuC change in 9/10?

9/10 looks easy but okay. I'm going to Cc Jani for series and hope for
the best.
2/10 is needed for the XE driver since it shares code with i915. It
seems fine otherwise. I can post them one-by-one if this makes it easier
for CI. Patches like 2/10 or 8/10 should make no impact on CI.

Thank you for the sign of life ;)

> Regards,
> 
> Tvrtko

Sebastian
Rodrigo Vivi June 11, 2024, 10:25 p.m. UTC | #4 
On Tue, Jun 11, 2024 at 05:14:26PM +0200, Sebastian Andrzej Siewior wrote:
> On 2024-06-11 14:06:00 [+0100], Tvrtko Ursulin wrote:
> > 
> > Hi Sebastian,
> Hi Tvrtko,
> 
> > Previous CI results have unfortunately expired by now. I have tried
> > re-queuing it but it also does not apply any longer so I'm afraid you will
> > have to respin before anyone can see the results.
> 
> No worries, I rebased it for latest RT release, I can respost them.
> 
> > And this is not to say that I can promise someone will look at it or when.
> > Maybe Jani you could ask for volunteers regarding the display related
> > patches (head of the series) and Rodrigo you about the GuC change in 9/10?
> 
> 9/10 looks easy but okay.

That is indeed the obvious place.

> I'm going to Cc Jani for series and hope for
> the best.
> 2/10 is needed for the XE driver since it shares code with i915. 

I believe you meant patch 1 right?
We are trying to eliminate the
#if I915
for the shared display code with Xe... we probably need to think
more deeply about that.

> It
> seems fine otherwise. I can post them one-by-one if this makes it easier
> for CI. Patches like 2/10 or 8/10 should make no impact on CI.
> 
> Thank you for the sign of life ;)
> 
> > Regards,
> > 
> > Tvrtko
> 
> Sebastian
Sebastian Andrzej Siewior June 13, 2024, 8:36 a.m. UTC | #5 
On 2024-06-11 18:25:07 [-0400], Rodrigo Vivi wrote:
> > 2/10 is needed for the XE driver since it shares code with i915. 
> 
> I believe you meant patch 1 right?
> We are trying to eliminate the
> #if I915
> for the shared display code with Xe... we probably need to think
> more deeply about that.

Maybe, my notes say otherwise but I could have slipped in the patch
number while looking up… I remember I noticed that the uncore lock isn't
used, it was only used on my "older" hardware.
Anyway, I could double check if this becomes urgent for some reason.

Sebastian