blob: 61229390d07a917675e7bdcee14ac561fa5965e5 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
|
<chapter xmlns="http://docbook.org/ns/docbook"
xmlns:xlink="http://www.w3.org/1999/xlink"
xmlns:xi="http://www.w3.org/2001/XInclude"
version="5.0"
xml:id="sec-gpu-accel">
<title>GPU acceleration</title>
<para>
NixOS provides various APIs that benefit from GPU hardware
acceleration, such as VA-API and VDPAU for video playback; OpenGL and
Vulkan for 3D graphics; and OpenCL for general-purpose computing.
This chapter describes how to set up GPU hardware acceleration (as far
as this is not done automatically) and how to verify that hardware
acceleration is indeed used.
</para>
<para>
Most of the aforementioned APIs are agnostic with regards to which
display server is used. Consequently, these instructions should apply
both to the X Window System and Wayland compositors.
</para>
<section xml:id="sec-gpu-accel-opencl">
<title>OpenCL</title>
<para>
<link xlink:href="https://en.wikipedia.org/wiki/OpenCL">OpenCL</link> is a
general compute API. It is used by various applications such as
Blender and Darktable to accelerate certain operations.
</para>
<para>
OpenCL applications load drivers through the <emphasis>Installable Client
Driver</emphasis> (ICD) mechanism. In this mechanism, an ICD file
specifies the path to the OpenCL driver for a particular GPU family.
In NixOS, there are two ways to make ICD files visible to the ICD
loader. The first is through the <varname>OCL_ICD_VENDORS</varname>
environment variable. This variable can contain a directory which
is scanned by the ICL loader for ICD files. For example:
<screen><prompt>$</prompt> export \
OCL_ICD_VENDORS=`nix-build '<nixpkgs>' --no-out-link -A rocm-opencl-icd`/etc/OpenCL/vendors/</screen>
</para>
<para>
The second mechanism is to add the OpenCL driver package to
<xref linkend="opt-hardware.opengl.extraPackages"/>. This links the
ICD file under <filename>/run/opengl-driver</filename>, where it will
be visible to the ICD loader.
</para>
<para>
The proper installation of OpenCL drivers can be verified through
the <command>clinfo</command> command of the <package>clinfo</package>
package. This command will report the number of hardware devides
that is found and give detailed information for each device:
</para>
<screen><prompt>$</prompt> clinfo | head -n3
Number of platforms 1
Platform Name AMD Accelerated Parallel Processing
Platform Vendor Advanced Micro Devices, Inc.</screen>
<section xml:id="sec-gpu-accel-opencl-amd">
<title>AMD</title>
<para>
Modern AMD <link
xlink:href="https://en.wikipedia.org/wiki/Graphics_Core_Next">Graphics
Core Next</link> (GCN) GPUs are supported through the
<package>rocm-opencl-icd</package> package. Adding this package to
<xref linkend="opt-hardware.opengl.extraPackages"/> enables OpenCL
support. However, OpenCL Image support is provided through the
non-free <package>rocm-runtime-ext</package> package. This package can
be added to the same configuration option, but requires that
<varname>allowUnfree</varname> option is is enabled for nixpkgs. Full
OpenCL support on supported AMD GPUs is thus enabled as follows:
<programlisting><xref linkend="opt-hardware.opengl.extraPackages"/> = [
rocm-opencl-icd
rocm-runtime-ext
];</programlisting>
</para>
<para>
It is also possible to use the OpenCL Image extension without a
system-wide installation of the <package>rocm-runtime-ext</package>
package by setting the <varname>ROCR_EXT_DIR</varname> environment
variable to the directory that contains the extension:
<screen><prompt>$</prompt> export \
ROCR_EXT_DIR=`nix-build '<nixpkgs>' --no-out-link -A rocm-runtime-ext`/lib/rocm-runtime-ext</screen>
</para>
<para>
With either approach, you can verify that OpenCL Image support
is indeed working with the <command>clinfo</command> command:
<screen><prompt>$</prompt> clinfo | grep Image
Image support Yes</screen>
</para>
</section>
</section>
</chapter>
|