<html>
<head>
<base href="https://bugs.freedesktop.org/">
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - ~10% perf drop in Sascha Willems Vulkan Multithreading demo"
href="https://bugs.freedesktop.org/show_bug.cgi?id=109055">109055</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>~10% perf drop in Sascha Willems Vulkan Multithreading demo
</td>
</tr>
<tr>
<th>Product</th>
<td>Mesa
</td>
</tr>
<tr>
<th>Version</th>
<td>git
</td>
</tr>
<tr>
<th>Hardware</th>
<td>Other
</td>
</tr>
<tr>
<th>OS</th>
<td>All
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>medium
</td>
</tr>
<tr>
<th>Component</th>
<td>Drivers/Vulkan/intel
</td>
</tr>
<tr>
<th>Assignee</th>
<td>intel-3d-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>eero.t.tamminen@intel.com
</td>
</tr>
<tr>
<th>QA Contact</th>
<td>intel-3d-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>CC</th>
<td>jason@jlekstrand.net
</td>
</tr></table>
<p>
<div>
<pre>Setup:
* SKL or KBL device (don't have data from others)
* Ubuntu 18.04 / Unity
* drm-tip v4.19 or newer kernel
* git version of X with modifiers (dmabuf capable) enabled
* Mesa git version
Test-case:
* multithreading --fullscreen --benchmark --benchwarmup 3 --benchruntime 20
Result:
* FPS drops by 5-10%
Between following Mesa commits:
41c8f991379d1a 2018-11-12 18:28:04 util: Fix warning in u_cpu_detect on non-x86
25b48e3df93dee 2018-11-14 12:12:09 st/xa: Bump minor
Along with the perf drop, one can see both CPU & GPU power usage drops
(according to RAPL), and GPU spending 30-40% in RC6 instead of 0%.
I.e. there's a Mesa change that makes this GPU test CPU bound.
I didn't see any significant perf changes in other benchmarks (Vulkan or GL).</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are the assignee for the bug.</li>
<li>You are the QA Contact for the bug.</li>
</ul>
</body>
</html>