<html>
<head>
<base href="https://bugs.freedesktop.org/">
</head>
<body>
<p>
<div>
<b><a class="bz_bug_link
bz_status_NEW "
title="NEW - Radeon: heavy r300 performance drop regression between 11.x and 19.x"
href="https://bugs.freedesktop.org/show_bug.cgi?id=110781#c5">Comment # 5</a>
on <a class="bz_bug_link
bz_status_NEW "
title="NEW - Radeon: heavy r300 performance drop regression between 11.x and 19.x"
href="https://bugs.freedesktop.org/show_bug.cgi?id=110781">bug 110781</a>
from <span class="vcard"><a class="email" href="mailto:u9vata@gmail.com" title="Richard Thier <u9vata@gmail.com>"> <span class="fn">Richard Thier</span></a>
</span></b>
<pre>Still fast with mesa 17.2.8 and X.Org X Server 1.19.5
The problem is somewhere between 17.x and 19.x mesa versions (and corresponding
xorg).
Also I have made an strace when it is good in one older system to see number of
CREATE and CLOSE ioctl calls (also the number of CS ioctl calls) are a
magnitude smaller than in case of 19.x!
For example 10-20 seconds of glxgears running leads to 9-10 calls to
DRM_IOCTL_RADEON_GEM_CREATE on mesa 17.2.8 while it leads to 708 (!!!) number
of same calls in the same time period on mesa 19.x! This is surely a quite big
of a difference!
The similar pattern in 17.x is never creating a new gem object:
...
ioctl(6, DRM_IOCTL_RADEON_GEM_WAIT_IDLE, 0xbfcf9f04) = 0 <0.000055>
ioctl(6, DRM_IOCTL_RADEON_GEM_BUSY, 0xbfcf9d44) = 0 <0.000022>
ioctl(6, DRM_IOCTL_RADEON_CS, 0xb307d03c) = 0 <0.000089>
ioctl(6, DRM_IOCTL_RADEON_GEM_WAIT_IDLE, 0xbfcf9f04) = 0 <0.000053>
ioctl(6, DRM_IOCTL_RADEON_GEM_BUSY, 0xbfcf9d44) = 0 <0.000023>
ioctl(6, DRM_IOCTL_RADEON_CS, 0xb30910d0) = 0 <0.000095>
ioctl(6, DRM_IOCTL_RADEON_GEM_WAIT_IDLE, 0xbfcf9f04) = 0 <0.000054>
ioctl(6, DRM_IOCTL_RADEON_GEM_BUSY, 0xbfcf9d44) = 0 <0.000023>
ioctl(6, DRM_IOCTL_RADEON_CS, 0xb307d03c) = 0 <0.000090>
...
Sometimes when the *_BUSY ioctl call returns -1, it issues a CREATE, but
otherwise not.
I think GEM is some kind of memory handler for the GPU (just like "ttm" in the
perf output) and I think something have messed up with memory handling schemes
for Mobility Radeon 200M (r300) at some mesa update between 17.x and 19.x.
Will try to bisect a closer version as 17.2.8 is from 2017.12.22 in time...</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are the assignee for the bug.</li>
</ul>
</body>
</html>