<html>
<head>
<base href="https://bugs.freedesktop.org/">
</head>
<body><span class="vcard"><a class="email" href="mailto:kenneth@whitecape.org" title="Kenneth Graunke <kenneth@whitecape.org>"> <span class="fn">Kenneth Graunke</span></a>
</span> changed
<a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [GEN9+] 5% performance drop + misrendering in GfxBench Manhattan 3.0 & CarChase from "i965: Disable auxiliary buffers when there are self-dependencies""
href="https://bugs.freedesktop.org/show_bug.cgi?id=103258">bug 103258</a>
<br>
<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>What</th>
<th>Removed</th>
<th>Added</th>
</tr>
<tr>
<td style="text-align:right;">Status</td>
<td>ASSIGNED
</td>
<td>RESOLVED
</td>
</tr>
<tr>
<td style="text-align:right;">Resolution</td>
<td>---
</td>
<td>FIXED
</td>
</tr></table>
<p>
<div>
<b><a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [GEN9+] 5% performance drop + misrendering in GfxBench Manhattan 3.0 & CarChase from "i965: Disable auxiliary buffers when there are self-dependencies""
href="https://bugs.freedesktop.org/show_bug.cgi?id=103258#c12">Comment # 12</a>
on <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED FIXED - [GEN9+] 5% performance drop + misrendering in GfxBench Manhattan 3.0 & CarChase from "i965: Disable auxiliary buffers when there are self-dependencies""
href="https://bugs.freedesktop.org/show_bug.cgi?id=103258">bug 103258</a>
from <span class="vcard"><a class="email" href="mailto:kenneth@whitecape.org" title="Kenneth Graunke <kenneth@whitecape.org>"> <span class="fn">Kenneth Graunke</span></a>
</span></b>
<pre>The performance regression should be fixed by the series ending in:
commit 82144b7392d1651167cbfd4746aea6a14d5aff46
Author: Kenneth Graunke <<a href="mailto:kenneth@whitecape.org">kenneth@whitecape.org</a>>
Date: Thu Oct 12 20:47:41 2017 -0700
i965: Don't disable aux buffers for non-overlapping miplevels.
Meta's GenerateMipmap implementation binds the same image for both
sampling and rendering - but it samples from one miplevel while
rendering the next. This is a false self-dependency, and there's
no need to disable auxiliary buffers in this case. In fact, we really
want to leave it enabled so the new miplevels gain color compression.
Thankfully, the texture object's _MaxLevel is always one shy of the
miplevel being rendered. So we can simply check if irb->mt_level is
overlaps with the texture's defined levels. If not, there's no self-
dependency and we can leave the auxiliary buffers enabled.
Fixes a performance regression in GFXBench4 Car Chase, which apparently
calls glGenerateMipmap() on every frame.
Bugzilla: <a class="bz_bug_link
bz_status_RESOLVED bz_closed"
title="RESOLVED DUPLICATE - Performance regression: car chase, manhattan"
href="show_bug.cgi?id=103247">https://bugs.freedesktop.org/show_bug.cgi?id=103247</a>
Reviewed-by: Topi Pohjolainen <<a href="mailto:topi.pohjolainen@intel.com">topi.pohjolainen@intel.com</a>>
Reviewed-by; Jason Ekstrand <<a href="mailto:jason@jlekstrand.net">jason@jlekstrand.net</a>>
I'm still not sure why the rendering changed - there's probably a bug there
still - but I don't have time to investigate that right now.</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are the QA Contact for the bug.</li>
</ul>
</body>
</html>