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<div class="moz-cite-prefix">Well we still need implicit sync or
otherwise the GPU scheduler would pick up the jobs in the wrong
order.<br>
<br>
See without this when we have the following sequence of
submission:<br>
<br>
Client IB1 using buffer A<br>
Client IB2<br>
X IB1 using buffer A<br>
<br>
We could end up with the execution order<br>
<br>
X IB1 using buffer A<br>
Client IB1 using buffer A<br>
Client IB2<br>
<br>
And that is not correct. The scheduler is only allowed to do the
following:<br>
<br>
Client IB1 using buffer A<br>
X IB1 using buffer A<br>
Client IB2<br>
<br>
And that's what implicit sync is taking care of.<br>
<br>
Christian.<br>
<br>
Am 26.05.20 um 00:07 schrieb Marek Olšák:<br>
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<div>If a user mode driver is changed to rely on the existence
of implicit sync, it results in corruption and flickering as
reported here: <a
href="https://gitlab.freedesktop.org/mesa/mesa/-/issues/2950"
moz-do-not-send="true">https://gitlab.freedesktop.org/mesa/mesa/-/issues/2950</a></div>
<div><br>
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<div>Marek<br>
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<br>
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<div dir="ltr" class="gmail_attr">On Mon, May 25, 2020 at 6:05
PM Marek Olšák <<a href="mailto:maraeo@gmail.com"
moz-do-not-send="true">maraeo@gmail.com</a>> wrote:<br>
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<div>Hi Christian,</div>
<div><br>
</div>
<div>Bas and Michel wanted to discuss this. The main
disadvantage of no implicit (pipeline) sync within the
same queue is that we get lower performance and lower GPU
utilization in some cases.<br>
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<div><br>
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<div>We actually never really needed the kernel to have
implicit sync, because all user mode drivers contained
hacks to work without it.</div>
<div><br>
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<div>Marek<br>
</div>
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