<div dir="auto">Hi David,<div dir="auto"><br></div><div dir="auto">Explicit sync has nothing to do with this. This is for implicit sync, which is required by DRI3. This fix allows removing existing inefficiencies from drivers, so it's a good thing.</div><div dir="auto"><br></div><div dir="auto">Marek</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed., Jun. 10, 2020, 03:56 Chunming Zhou, <<a href="mailto:zhoucm1@amd.com">zhoucm1@amd.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<p><br>
</p>
<div>在 2020/6/10 15:41, Christian König 写道:<br>
</div>
<blockquote type="cite">
<div>That's true, but for now we are stuck
with the implicit sync for quite a number of use cases.<br>
<br>
My problem is rather that we already tried this and it backfired
immediately.<br>
<br>
I do remember that it was your patch who introduced the pipeline
sync flag handling and I warned that this could be problematic.
You then came back with a QA result saying that this is indeed
causing a huge performance drop in one test case and we need to
do something else. Together we then came up with the different
handling between implicit and explicit sync.<br>
</div>
</blockquote>
<p>Isn't pipeline sync flag to fix some issue because of parralel
execution between jobs in one pipeline? I really don't have this
memory in mind why that's realted to this, Or do you mean extra
sync hides many other potential issues?</p>
<p>Anyway, when I go through Vulkan WSI code, the synchronization
isn't so smooth between OS window system. And when I saw Jason
drives explicit sync through the whole Linux ecosystem like
Android window system does, I feel that's really a good direction.</p>
<p>-David<br>
</p>
<blockquote type="cite">
<div> <br>
But I can't find that stupid mail thread any more. I knew that
it was a couple of years ago when we started with the explicit
sync for Vulkan.<br>
<br>
Christian.<br>
<br>
Am 10.06.20 um 08:29 schrieb Zhou, David(ChunMing):<br>
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<blockquote type="cite">
<div>
<p style="margin:0in;margin-bottom:.0001pt"><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:#0078d7">[AMD
Official Use Only - Internal Distribution Only]</span><u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">Not sue if this is right direction, I
think usermode wants all synchronizations to be explicit.
Implicit sync often confuses people who don’t know its
history. I remember Jason from Intel is driving explicit
synchronization through the Linux ecosystem, which even
removes implicit sync of shared buffer.<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">-David<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<div style="border:none;border-top:solid #e1e1e1 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b>From:</b> amd-gfx <a href="mailto:amd-gfx-bounces@lists.freedesktop.org" target="_blank" rel="noreferrer"><amd-gfx-bounces@lists.freedesktop.org></a>
<b>On Behalf Of </b>Marek Olšák<br>
<b>Sent:</b> Tuesday, June 9, 2020 6:58 PM<br>
<b>To:</b> amd-gfx mailing list <a href="mailto:amd-gfx@lists.freedesktop.org" target="_blank" rel="noreferrer"><amd-gfx@lists.freedesktop.org></a><br>
<b>Subject:</b> [PATCH] drm/amdgpu: remove distinction
between explicit and implicit sync (v2)<u></u><u></u></p>
</div>
<p class="MsoNormal"><u></u> <u></u></p>
<div>
<div>
<p class="MsoNormal">Hi,<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
<div>
<p class="MsoNormal">This enables a full pipeline sync for
implicit sync. It's Christian's patch with the driver
version bumped. With this, user mode drivers don't have
to wait for idle at the end of gfx IBs.<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
<div>
<p class="MsoNormal">Any concerns?<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal"><u></u> <u></u></p>
</div>
<div>
<p class="MsoNormal">Thanks,<u></u><u></u></p>
</div>
<div>
<p class="MsoNormal">Marek<u></u><u></u></p>
</div>
</div>
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