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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>,
	Chris Wilson <chris@chris-wilson.co.uk>,
	Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>,
	linux-rt-users@vger.kernel.org, intel-gfx@lists.freedesktop.org,
	Jani Nikula <jani.nikula@linux.intel.com>,
	Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
	Rodrigo Vivi <rodrigo.vivi@intel.com>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [RFC] tentative fix for drm/i915/gt regression on preempt-rt
Date: Tue, 4 Jul 2023 11:25:32 +0200	[thread overview]
Message-ID: <20230704092532.k-Fi14oC@linutronix.de> (raw)
In-Reply-To: <bf4658a8-cf10-92c1-5e48-d674ad0e5c46@linux.intel.com>

On 2023-07-04 09:02:07 [+0100], Tvrtko Ursulin wrote:

> Lets make it a two patch series and then see. First patch to see if we can
> really get away without the top level preempt_disable, and then second patch
> to see if we can get away with preemptible short sleeps too.
oki.

> I guess on RT the top priority is consistent scheduling latency and not so
> much potential UI latency in some edge cases? Saying that because if waiting
I would says, yes. If you do RT and you provide some kind of GUI then
you prefer to meet your deadlines for your RT load over some UI latency.

> on the hw reset is made preemptible, _in theory_ it can prolong the reset
> completion (as observed by i915), and so result in more UI glitching than it
> normally would. Could be a theoretical point only because it requires both
> CPU over-subscribe and GPU hangs. It could also easily be that the reset
> path is only one path, and not so interesting one even, which can cause this
> on RT.

I see.

> Regards,
> 
> Tvrtko

Sebastian

      reply	other threads:[~2023-07-04  9:25 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-06-23  0:57 [RFC] tentative fix for drm/i915/gt regression on preempt-rt Paul Gortmaker
2023-06-30 13:09 ` Sebastian Andrzej Siewior
2023-07-03 15:30   ` Tvrtko Ursulin
2023-07-03 16:12     ` Sebastian Andrzej Siewior
2023-07-04  8:02       ` Tvrtko Ursulin
2023-07-04  9:25         ` Sebastian Andrzej Siewior [this message]

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