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
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<title>Environment Variables</title>
<link rel="stylesheet" type="text/css" href="mesa.css">
</head>
<body>
<div class="header">
<h1>The Mesa 3D Graphics Library</h1>
</div>
<iframe src="contents.html"></iframe>
<div class="content">
<h1>Environment Variables</h1>
<p>
Normally, no environment variables need to be set. Most of the environment
variables used by Mesa/Gallium are for debugging purposes, but they can
sometimes be useful for debugging end-user issues.
</p>
<h2>LibGL environment variables</h2>
<ul>
<li>LIBGL_DEBUG - If defined debug information will be printed to stderr.
If set to 'verbose' additional information will be printed.
<li>LIBGL_DRIVERS_PATH - colon-separated list of paths to search for DRI drivers
<li>LIBGL_ALWAYS_INDIRECT - forces an indirect rendering context/connection.
<li>LIBGL_ALWAYS_SOFTWARE - if set, always use software rendering
<li>LIBGL_NO_DRAWARRAYS - if set do not use DrawArrays GLX protocol (for debugging)
<li>LIBGL_SHOW_FPS - print framerate to stdout based on the number of glXSwapBuffers
calls per second.
<li>LIBGL_DRI3_DISABLE - disable DRI3 if set (the value does not matter)
</ul>
<h2>Core Mesa environment variables</h2>
<ul>
<li>MESA_NO_ASM - if set, disables all assembly language optimizations
<li>MESA_NO_MMX - if set, disables Intel MMX optimizations
<li>MESA_NO_3DNOW - if set, disables AMD 3DNow! optimizations
<li>MESA_NO_SSE - if set, disables Intel SSE optimizations
<li>MESA_NO_ERROR - if set error checking is disabled as per KHR_no_error.
This will result in undefined behaviour for invalid use of the api, but
can reduce CPU use for apps that are known to be error free.</li>
<li>MESA_DEBUG - if set, error messages are printed to stderr. For example,
if the application generates a GL_INVALID_ENUM error, a corresponding error
message indicating where the error occurred, and possibly why, will be
printed to stderr.<br>
For release builds, MESA_DEBUG defaults to off (no debug output).
MESA_DEBUG accepts the following comma-separated list of named
flags, which adds extra behaviour to just set MESA_DEBUG=1:
<ul>
<li>silent - turn off debug messages. Only useful for debug builds.</li>
<li>flush - flush after each drawing command</li>
<li>incomplete_tex - extra debug messages when a texture is incomplete</li>
<li>incomplete_fbo - extra debug messages when a fbo is incomplete</li>
<li>context - create a debug context (see GLX_CONTEXT_DEBUG_BIT_ARB) and
print error and performance messages to stderr (or MESA_LOG_FILE).</li>
</ul>
<li>MESA_LOG_FILE - specifies a file name for logging all errors, warnings,
etc., rather than stderr
<li>MESA_TEX_PROG - if set, implement conventional texture env modes with
fragment programs (intended for developers only)
<li>MESA_TNL_PROG - if set, implement conventional vertex transformation
operations with vertex programs (intended for developers only).
Setting this variable automatically sets the MESA_TEX_PROG variable as well.
<li>MESA_EXTENSION_OVERRIDE - can be used to enable/disable extensions.
A value such as "GL_EXT_foo -GL_EXT_bar" will enable the GL_EXT_foo extension
and disable the GL_EXT_bar extension.
<li>MESA_EXTENSION_MAX_YEAR - The GL_EXTENSIONS string returned by Mesa is sorted
by extension year.
If this variable is set to year X, only extensions defined on or before year
X will be reported.
This is to work-around a bug in some games where the extension string is
copied into a fixed-size buffer without truncating.
If the extension string is too long, the buffer overrun can cause the game
to crash.
This is a work-around for that.
<li>MESA_GL_VERSION_OVERRIDE - changes the value returned by
glGetString(GL_VERSION) and possibly the GL API type.
<ul>
<li> The format should be MAJOR.MINOR[FC]
<li> FC is an optional suffix that indicates a forward compatible context.
This is only valid for versions >= 3.0.
<li> GL versions < 3.0 are set to a compatibility (non-Core) profile
<li> GL versions = 3.0, see below
<li> GL versions > 3.0 are set to a Core profile
<li> Examples: 2.1, 3.0, 3.0FC, 3.1, 3.1FC
<ul>
<li> 2.1 - select a compatibility (non-Core) profile with GL version 2.1
<li> 3.0 - select a compatibility (non-Core) profile with GL version 3.0
<li> 3.0FC - select a Core+Forward Compatible profile with GL version 3.0
<li> 3.1 - select a Core profile with GL version 3.1
<li> 3.1FC - select a Core+Forward Compatible profile with GL version 3.1
</ul>
<li> Mesa may not really implement all the features of the given version.
(for developers only)
</ul>
<li>MESA_GLES_VERSION_OVERRIDE - changes the value returned by
glGetString(GL_VERSION) for OpenGL ES.
<ul>
<li> The format should be MAJOR.MINOR
<li> Examples: 2.0, 3.0, 3.1
<li> Mesa may not really implement all the features of the given version.
(for developers only)
</ul>
<li>MESA_GLSL_VERSION_OVERRIDE - changes the value returned by
glGetString(GL_SHADING_LANGUAGE_VERSION). Valid values are integers, such as
"130". Mesa will not really implement all the features of the given language version
if it's higher than what's normally reported. (for developers only)
<li>MESA_GLSL_CACHE_DISABLE - if set, disables the GLSL shader cache
<li>MESA_GLSL_CACHE_MAX_SIZE - if set, determines the maximum size of
the on-disk cache of compiled GLSL programs. Should be set to a number
optionally followed by 'K', 'M', or 'G' to specify a size in
kilobytes, megabytes, or gigabytes. By default, gigabytes will be
assumed. And if unset, a maximum size of 1GB will be used. Note: A separate
cache might be created for each architecture that Mesa is installed for on
your system. For example under the default settings you may end up with a 1GB
cache for x86_64 and another 1GB cache for i386.
<li>MESA_GLSL_CACHE_DIR - if set, determines the directory to be used
for the on-disk cache of compiled GLSL programs. If this variable is
not set, then the cache will be stored in $XDG_CACHE_HOME/mesa (if
that variable is set), or else within .cache/mesa within the user's
home directory.
<li>MESA_GLSL - <a href="shading.html#envvars">shading language compiler options</a>
<li>MESA_NO_MINMAX_CACHE - when set, the minmax index cache is globally disabled.
</ul>
<h2>Mesa Xlib driver environment variables</h2>
<p>
The following are only applicable to the Mesa Xlib software driver.
See the <a href="xlibdriver.html">Xlib software driver page</a> for details.
</p>
<ul>
<li>MESA_RGB_VISUAL - specifies the X visual and depth for RGB mode
<li>MESA_CI_VISUAL - specifies the X visual and depth for CI mode
<li>MESA_BACK_BUFFER - specifies how to implement the back color buffer,
either "pixmap" or "ximage"
<li>MESA_GAMMA - gamma correction coefficients for red, green, blue channels
<li>MESA_XSYNC - enable synchronous X behavior (for debugging only)
<li>MESA_GLX_FORCE_CI - if set, force GLX to treat 8bpp visuals as CI visuals
<li>MESA_GLX_FORCE_ALPHA - if set, forces RGB windows to have an alpha channel.
<li>MESA_GLX_DEPTH_BITS - specifies default number of bits for depth buffer.
<li>MESA_GLX_ALPHA_BITS - specifies default number of bits for alpha channel.
</ul>
<h2>i945/i965 driver environment variables (non-Gallium)</h2>
<ul>
<li>INTEL_NO_HW - if set to 1, prevents batches from being submitted to the hardware.
This is useful for debugging hangs, etc.</li>
<li>INTEL_DEBUG - a comma-separated list of named flags, which do various things:
<ul>
<li>ann - annotate IR in assembly dumps</li>
<li>aub - dump batches into an AUB trace for use with simulation tools</li>
<li>bat - emit batch information</li>
<li>blit - emit messages about blit operations</li>
<li>blorp - emit messages about the blorp operations (blits & clears)</li>
<li>buf - emit messages about buffer objects</li>
<li>clip - emit messages about the clip unit (for old gens, includes the CLIP program)</li>
<li>color - use color in output</li>
<li>cs - dump shader assembly for compute shaders</li>
<li>do32 - generate compute shader SIMD32 programs even if workgroup size doesn't exceed the SIMD16 limit</li>
<li>dri - emit messages about the DRI interface</li>
<li>fbo - emit messages about framebuffers</li>
<li>fs - dump shader assembly for fragment shaders</li>
<li>gs - dump shader assembly for geometry shaders</li>
<li>hex - print instruction hex dump with the disassembly</li>
<li>l3 - emit messages about the new L3 state during transitions</li>
<li>miptree - emit messages about miptrees</li>
<li>no8 - don't generate SIMD8 fragment shader</li>
<li>no16 - suppress generation of 16-wide fragment shaders. useful for debugging broken shaders</li>
<li>nocompact - disable instruction compaction</li>
<li>nodualobj - suppress generation of dual-object geometry shader code</li>
<li>norbc - disable single sampled render buffer compression</li>
<li>optimizer - dump shader assembly to files at each optimization pass and iteration that make progress</li>
<li>perf - emit messages about performance issues</li>
<li>perfmon - emit messages about AMD_performance_monitor</li>
<li>pix - emit messages about pixel operations</li>
<li>prim - emit messages about drawing primitives</li>
<li>sf - emit messages about the strips & fans unit (for old gens, includes the SF program)</li>
<li>shader_time - record how much GPU time is spent in each shader</li>
<li>spill_fs - force spilling of all registers in the scalar backend (useful to debug spilling code)</li>
<li>spill_vec4 - force spilling of all registers in the vec4 backend (useful to debug spilling code)</li>
<li>state - emit messages about state flag tracking</li>
<li>sync - after sending each batch, emit a message and wait for that batch to finish rendering</li>
<li>tcs - dump shader assembly for tessellation control shaders</li>
<li>tes - dump shader assembly for tessellation evaluation shaders</li>
<li>tex - emit messages about textures.</li>
<li>urb - emit messages about URB setup</li>
<li>vec4 - force vec4 mode in vertex shader</li>
<li>vert - emit messages about vertex assembly</li>
<li>vs - dump shader assembly for vertex shaders</li>
</ul>
<li>INTEL_PRECISE_TRIG - if set to 1, true or yes, then the driver prefers
accuracy over performance in trig functions.</li>
</ul>
<h2>Radeon driver environment variables (radeon, r200, and r300g)</h2>
<ul>
<li>RADEON_NO_TCL - if set, disable hardware-accelerated Transform/Clip/Lighting.
</ul>
<h2>EGL environment variables</h2>
<p>
Mesa EGL supports different sets of environment variables. See the
<a href="egl.html">Mesa EGL</a> page for the details.
</p>
<h2>Gallium environment variables</h2>
<ul>
<li>GALLIUM_HUD - draws various information on the screen, like framerate,
cpu load, driver statistics, performance counters, etc.
Set GALLIUM_HUD=help and run e.g. glxgears for more info.
<li>GALLIUM_HUD_PERIOD - sets the hud update rate in seconds (float). Use zero
to update every frame. The default period is 1/2 second.
<li>GALLIUM_HUD_VISIBLE - control default visibility, defaults to true.
<li>GALLIUM_HUD_TOGGLE_SIGNAL - toggle visibility via user specified signal.
Especially useful to toggle hud at specific points of application and
disable for unencumbered viewing the rest of the time. For example, set
GALLIUM_HUD_VISIBLE to false and GALLIUM_HUD_TOGGLE_SIGNAL to 10 (SIGUSR1).
Use kill -10 <pid> to toggle the hud as desired.
<li>GALLIUM_HUD_DUMP_DIR - specifies a directory for writing the displayed
hud values into files.
<li>GALLIUM_DRIVER - useful in combination with LIBGL_ALWAYS_SOFTWARE=1 for
choosing one of the software renderers "softpipe", "llvmpipe" or "swr".
<li>GALLIUM_LOG_FILE - specifies a file for logging all errors, warnings, etc.
rather than stderr.
<li>GALLIUM_PRINT_OPTIONS - if non-zero, print all the Gallium environment
variables which are used, and their current values.
<li>GALLIUM_DUMP_CPU - if non-zero, print information about the CPU on start-up
<li>TGSI_PRINT_SANITY - if set, do extra sanity checking on TGSI shaders and
print any errors to stderr.
<LI>DRAW_FSE - ???
<LI>DRAW_NO_FSE - ???
<li>DRAW_USE_LLVM - if set to zero, the draw module will not use LLVM to execute
shaders, vertex fetch, etc.
<li>ST_DEBUG - controls debug output from the Mesa/Gallium state tracker.
Setting to "tgsi", for example, will print all the TGSI shaders.
See src/mesa/state_tracker/st_debug.c for other options.
</ul>
<h3>Clover state tracker environment variables</h3>
<ul>
<li>CLOVER_EXTRA_BUILD_OPTIONS - allows specifying additional compiler and linker
options. Specified options are appended after the options set by the OpenCL
program in clBuildProgram.
<li>CLOVER_EXTRA_COMPILE_OPTIONS - allows specifying additional compiler
options. Specified options are appended after the options set by the OpenCL
program in clCompileProgram.
<li>CLOVER_EXTRA_LINK_OPTIONS - allows specifying additional linker
options. Specified options are appended after the options set by the OpenCL
program in clLinkProgram.
</ul>
<h3>Softpipe driver environment variables</h3>
<ul>
<li>SOFTPIPE_DUMP_FS - if set, the softpipe driver will print fragment shaders
to stderr
<li>SOFTPIPE_DUMP_GS - if set, the softpipe driver will print geometry shaders
to stderr
<li>SOFTPIPE_NO_RAST - if set, rasterization is no-op'd. For profiling purposes.
<li>SOFTPIPE_USE_LLVM - if set, the softpipe driver will try to use LLVM JIT for
vertex shading processing.
</ul>
<h3>LLVMpipe driver environment variables</h3>
<ul>
<li>LP_NO_RAST - if set LLVMpipe will no-op rasterization
<li>LP_DEBUG - a comma-separated list of debug options is accepted. See the
source code for details.
<li>LP_PERF - a comma-separated list of options to selectively no-op various
parts of the driver. See the source code for details.
<li>LP_NUM_THREADS - an integer indicating how many threads to use for rendering.
Zero turns off threading completely. The default value is the number of CPU
cores present.
</ul>
<h3>VMware SVGA driver environment variables</h3>
<ul>
<li>SVGA_FORCE_SWTNL - force use of software vertex transformation
<li>SVGA_NO_SWTNL - don't allow software vertex transformation fallbacks
(will often result in incorrect rendering).
<li>SVGA_DEBUG - for dumping shaders, constant buffers, etc. See the code
for details.
<li>See the driver code for other, lesser-used variables.
</ul>
<h3>VA-API state tracker environment variables</h3>
<ul>
<li>VAAPI_MPEG4_ENABLED - enable MPEG4 for VA-API, disabled by default.
</ul>
<h3>VC4 driver environment variables</h3>
<ul>
<li>VC4_DEBUG - a comma-separated list of named flags, which do various things:
<ul>
<li>cl - dump command list during creation</li>
<li>qpu - dump generated QPU instructions</li>
<li>qir - dump QPU IR during program compile</li>
<li>nir - dump NIR during program compile</li>
<li>tgsi - dump TGSI during program compile</li>
<li>shaderdb - dump program compile information for shader-db analysis</li>
<li>perf - print during performance-related events</li>
<li>norast - skip actual hardware execution of commands</li>
<li>always_flush - flush after each draw call</li>
<li>always_sync - wait for finish after each flush</li>
<li>dump - write a GPU command stream trace file (VC4 simulator only)</li>
</ul>
</ul>
<p>
Other Gallium drivers have their own environment variables. These may change
frequently so the source code should be consulted for details.
</p>
</div>
</body>
</html>
|
