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
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
|
<!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">
The Mesa 3D Graphics Library
</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>
<dl>
<dt><code>LIBGL_DEBUG</code></dt>
<dd>If defined debug information will be printed to stderr.
If set to <code>verbose</code> additional information will be
printed.</dd>
<dt><code>LIBGL_DRIVERS_PATH</code></dt>
<dd>colon-separated list of paths to search for DRI drivers</dd>
<dt><code>LIBGL_ALWAYS_INDIRECT</code></dt>
<dd>if set to <code>true</code>, forces an indirect rendering
context/connection.</dd>
<dt><code>LIBGL_ALWAYS_SOFTWARE</code></dt>
<dd>if set to <code>true</code>, always use software rendering</dd>
<dt><code>LIBGL_NO_DRAWARRAYS</code></dt>
<dd>if set to <code>true</code>, do not use DrawArrays GLX protocol
(for debugging)</dd>
<dt><code>LIBGL_SHOW_FPS</code></dt>
<dd>print framerate to stdout based on the number of
<code>glXSwapBuffers</code> calls per second.</dd>
<dt><code>LIBGL_DRI3_DISABLE</code></dt>
<dd>disable DRI3 if set to <code>true</code>.</dd>
</dl>
<h2>Core Mesa environment variables</h2>
<dl>
<dt><code>MESA_NO_ASM</code></dt>
<dd>if set, disables all assembly language optimizations</dd>
<dt><code>MESA_NO_MMX</code></dt>
<dd>if set, disables Intel MMX optimizations</dd>
<dt><code>MESA_NO_3DNOW</code></dt>
<dd>if set, disables AMD 3DNow! optimizations</dd>
<dt><code>MESA_NO_SSE</code></dt>
<dd>if set, disables Intel SSE optimizations</dd>
<dt><code>MESA_NO_ERROR</code></dt>
<dd>if set to 1, error checking is disabled as per <code>KHR_no_error</code>.
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.</dd>
<dt><code>MESA_DEBUG</code></dt>
<dd>if set, error messages are printed to stderr. For example,
if the application generates a <code>GL_INVALID_ENUM</code> error, a
corresponding error message indicating where the error occurred, and
possibly why, will be printed to stderr. For release builds,
<code>MESA_DEBUG</code> defaults to off (no debug output).
<code>MESA_DEBUG</code> accepts the following comma-separated list of
named flags, which adds extra behaviour to just set
<code>MESA_DEBUG=1</code>:
<dl>
<dt><code>silent</code></dt>
<dd>turn off debug messages. Only useful for debug builds.</dd>
<dt><code>flush</code></dt>
<dd>flush after each drawing command</dd>
<dt><code>incomplete_tex</code></dt>
<dd>extra debug messages when a texture is incomplete</dd>
<dt><code>incomplete_fbo</code></dt>
<dd>extra debug messages when a fbo is incomplete</dd>
<dt><code>context</code></dt>
<dd>create a debug context (see <code>GLX_CONTEXT_DEBUG_BIT_ARB</code>)
and print error and performance messages to stderr (or
<code>MESA_LOG_FILE</code>).</dd>
</dl>
</dd>
<dt><code>MESA_LOG_FILE</code></dt>
<dd>specifies a file name for logging all errors, warnings,
etc., rather than stderr</dd>
<dt><code>MESA_TEX_PROG</code></dt>
<dd>if set, implement conventional texture env modes with
fragment programs (intended for developers only)</dd>
<dt><code>MESA_TNL_PROG</code></dt>
<dd>if set, implement conventional vertex transformation operations with
vertex programs (intended for developers only). Setting this variable
automatically sets the <code>MESA_TEX_PROG</code> variable as well.</dd>
<dt><code>MESA_EXTENSION_OVERRIDE</code></dt>
<dd>can be used to enable/disable extensions. A value such as
<code>GL_EXT_foo -GL_EXT_bar</code> will enable the
<code>GL_EXT_foo</code> extension and disable the
<code>GL_EXT_bar</code> extension.</dd>
<dt><code>MESA_EXTENSION_MAX_YEAR</code></dt>
<dd>The <code>GL_EXTENSIONS</code> 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.</dd>
<dt><code>MESA_GL_VERSION_OVERRIDE</code></dt>
<dd>changes the value returned by
<code>glGetString(GL_VERSION)</code> and possibly the GL API type.
<ul>
<li>The format should be <code>MAJOR.MINOR[FC|COMPAT]</code>
<li><code>FC</code> is an optional suffix that indicates a forward
compatible context. This is only valid for versions >= 3.0.
<li><code>COMPAT</code> is an optional suffix that indicates a
compatibility context or <code>GL_ARB_compatibility</code> support.
This is only valid for versions >= 3.1.
<li>GL versions <= 3.0 are set to a compatibility (non-Core)
profile
<li>GL versions = 3.1, depending on the driver, it may or may not
have the <code>ARB_compatibility</code> extension enabled.
<li>GL versions >= 3.2 are set to a Core profile
<li>Examples:
<dl>
<dt><code>2.1</code></dt>
<dd>select a compatibility (non-Core) profile with GL version 2.1.</dd>
<dt><code>3.0</code></dt>
<dd>select a compatibility (non-Core) profile with GL version 3.0.</dd>
<dt><code>3.0FC</code></dt>
<dd>select a Core+Forward Compatible profile with GL version 3.0.</dd>
<dt><code>3.1</code></dt>
<dd>select GL version 3.1 with <code>GL_ARB_compatibility</code>
enabled per the driver default.</dd>
<dt><code>3.1FC</code></dt>
<dd>select GL version 3.1 with forward compatibility and
<code>GL_ARB_compatibility</code> disabled.</dd>
<dt><code>3.1COMPAT</code></dt>
<dd>select GL version 3.1 with <code>GL_ARB_compatibility</code>
enabled.</dd>
<dt><code>X.Y</code></dt>
<dd>override GL version to X.Y without changing the profile.</dd>
<dt><code>X.YFC</code></dt>
<dd>select a Core+Forward Compatible profile with GL version X.Y.</dd>
<dt><code>X.YCOMPAT</code></dt>
<dd>select a Compatibility profile with GL version X.Y.</dd>
</dl>
<li>Mesa may not really implement all the features of the given
version. (for developers only)
</ul>
</dd>
<dt><code>MESA_GLES_VERSION_OVERRIDE</code></dt>
<dd>changes the value returned by <code>glGetString(GL_VERSION)</code>
for OpenGL ES.
<ul>
<li> The format should be <code>MAJOR.MINOR</code>
<li> Examples: <code>2.0</code>, <code>3.0</code>, <code>3.1</code>
<li> Mesa may not really implement all the features of the given version.
(for developers only)
</ul>
</dd>
<dt><code>MESA_GLSL_VERSION_OVERRIDE</code></dt>
<dd>changes the value returned by
<code>glGetString(GL_SHADING_LANGUAGE_VERSION)</code>.
Valid values are integers, such as <code>130</code>. 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)
</dd>
<dt><code>MESA_GLSL_CACHE_DISABLE</code></dt>
<dd>if set to <code>true</code>, disables the GLSL shader cache</dd>
<dt><code>MESA_GLSL_CACHE_MAX_SIZE</code></dt>
<dd>if set, determines the maximum size of the on-disk cache of compiled GLSL
programs. Should be set to a number optionally followed by <code>K</code>,
<code>M</code>, or <code>G</code> 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.</dd>
<dt><code>MESA_GLSL_CACHE_DIR</code></dt>
<dd>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 <code>$XDG_CACHE_HOME/mesa_shader_cache</code> (if that
variable is set), or else within <code>.cache/mesa_shader_cache</code>
within the user's home directory.
</dd>
<dt><code>MESA_GLSL</code></dt>
<dd><a href="shading.html#envvars">shading language compiler options</a></dd>
<dt><code>MESA_NO_MINMAX_CACHE</code></dt>
<dd>when set, the minmax index cache is globally disabled.</dd>
<dt><code>MESA_SHADER_CAPTURE_PATH</code></dt>
<dd>see <a href="shading.html#capture">Capturing Shaders</a></dd>
<dt><code>MESA_SHADER_DUMP_PATH</code> and <code>MESA_SHADER_READ_PATH</code></dt>
<dd>see <a href="shading.html#replacement">Experimenting with Shader Replacements</a></dd>
<dt><code>MESA_VK_VERSION_OVERRIDE</code></dt>
<dd>changes the Vulkan physical device version
as returned in <code>VkPhysicalDeviceProperties::apiVersion</code>.
<ul>
<li>The format should be <code>MAJOR.MINOR[.PATCH]</code></li>
<li>This will not let you force a version higher than the driver's
instance version as advertised by
<code>vkEnumerateInstanceVersion</code></li>
<li>This can be very useful for debugging but some features may not be
implemented correctly. (For developers only)</li>
</ul>
</dd>
</dl>
<h2>NIR passes enviroment variables</h2>
<p>
The following are only applicable for drivers that uses NIR, as they
modify the behaviour for the common NIR_PASS and NIR_PASS_V macros,
that wrap calls to NIR lowering/optimizations.
</p>
<dl>
<dt><code>NIR_PRINT</code></dt>
<dd>If defined, the resulting NIR shader will be printed out at each succesful NIR lowering/optimization call.</dd>
<dt><code>NIR_TEST_CLONE</code></dt>
<dd>If defined, cloning a NIR shader would be tested at each succesful NIR lowering/optimization call.</dd>
<dt><code>NIR_TEST_SERIALIZE</code></dt>
<dd>If defined, serialize and deserialize a NIR shader would be tested at each succesful NIR lowering/optimization call.</dd>
</dl>
<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>
<dl>
<dt><code>MESA_RGB_VISUAL</code></dt>
<dd>specifies the X visual and depth for RGB mode</dd>
<dt><code>MESA_CI_VISUAL</code></dt>
<dd>specifies the X visual and depth for CI mode</dd>
<dt><code>MESA_BACK_BUFFER</code></dt>
<dd>specifies how to implement the back color buffer, either
<code>pixmap</code> or <code>ximage</code></dd>
<dt><code>MESA_GAMMA</code></dt>
<dd>gamma correction coefficients for red, green, blue channels</dd>
<dt><code>MESA_XSYNC</code></dt>
<dd>enable synchronous X behavior (for debugging only)</dd>
<dt><code>MESA_GLX_FORCE_CI</code></dt>
<dd>if set, force GLX to treat 8bpp visuals as CI visuals</dd>
<dt><code>MESA_GLX_FORCE_ALPHA</code></dt>
<dd>if set, forces RGB windows to have an alpha channel.</dd>
<dt><code>MESA_GLX_DEPTH_BITS</code></dt>
<dd>specifies default number of bits for depth buffer.</dd>
<dt><code>MESA_GLX_ALPHA_BITS</code></dt>
<dd>specifies default number of bits for alpha channel.</dd>
</dl>
<h2>i945/i965 driver environment variables (non-Gallium)</h2>
<dl>
<dt><code>INTEL_NO_HW</code></dt>
<dd>if set to 1, prevents batches from being submitted to the hardware.
This is useful for debugging hangs, etc.</dd>
<dt><code>INTEL_DEBUG</code></dt>
<dd>a comma-separated list of named flags, which do various things:
<dl>
<dt><code>ann</code></dt>
<dd>annotate IR in assembly dumps</dd>
<dt><code>aub</code></dt>
<dd>dump batches into an AUB trace for use with simulation tools</dd>
<dt><code>bat</code></dt>
<dd>emit batch information</dd>
<dt><code>blit</code></dt>
<dd>emit messages about blit operations</dd>
<dt><code>blorp</code></dt>
<dd>emit messages about the blorp operations (blits & clears)</dd>
<dt><code>buf</code></dt>
<dd>emit messages about buffer objects</dd>
<dt><code>clip</code></dt>
<dd>emit messages about the clip unit (for old gens, includes the CLIP program)</dd>
<dt><code>color</code></dt>
<dd>use color in output</dd>
<dt><code>cs</code></dt>
<dd>dump shader assembly for compute shaders</dd>
<dt><code>do32</code></dt>
<dd>generate compute shader SIMD32 programs even if workgroup size doesn't exceed the SIMD16 limit</dd>
<dt><code>dri</code></dt>
<dd>emit messages about the DRI interface</dd>
<dt><code>fbo</code></dt>
<dd>emit messages about framebuffers</dd>
<dt><code>fs</code></dt>
<dd>dump shader assembly for fragment shaders</dd>
<dt><code>gs</code></dt>
<dd>dump shader assembly for geometry shaders</dd>
<dt><code>hex</code></dt>
<dd>print instruction hex dump with the disassembly</dd>
<dt><code>l3</code></dt>
<dd>emit messages about the new L3 state during transitions</dd>
<dt><code>miptree</code></dt>
<dd>emit messages about miptrees</dd>
<dt><code>no8</code></dt>
<dd>don't generate SIMD8 fragment shader</dd>
<dt><code>no16</code></dt>
<dd>suppress generation of 16-wide fragment shaders. useful for debugging broken shaders</dd>
<dt><code>nocompact</code></dt>
<dd>disable instruction compaction</dd>
<dt><code>nodualobj</code></dt>
<dd>suppress generation of dual-object geometry shader code</dd>
<dt><code>norbc</code></dt>
<dd>disable single sampled render buffer compression</dd>
<dt><code>optimizer</code></dt>
<dd>dump shader assembly to files at each optimization pass and iteration that make progress</dd>
<dt><code>perf</code></dt>
<dd>emit messages about performance issues</dd>
<dt><code>perfmon</code></dt>
<dd>emit messages about <code>AMD_performance_monitor</code></dd>
<dt><code>pix</code></dt>
<dd>emit messages about pixel operations</dd>
<dt><code>prim</code></dt>
<dd>emit messages about drawing primitives</dd>
<dt><code>reemit</code></dt>
<dd>mark all state dirty on each draw call</dd>
<dt><code>sf</code></dt>
<dd>emit messages about the strips & fans unit (for old gens, includes the SF program)</dd>
<dt><code>shader_time</code></dt>
<dd>record how much GPU time is spent in each shader</dd>
<dt><code>spill_fs</code></dt>
<dd>force spilling of all registers in the scalar backend (useful to debug spilling code)</dd>
<dt><code>spill_vec4</code></dt>
<dd>force spilling of all registers in the vec4 backend (useful to debug spilling code)</dd>
<dt><code>state</code></dt>
<dd>emit messages about state flag tracking</dd>
<dt><code>submit</code></dt>
<dd>emit batchbuffer usage statistics</dd>
<dt><code>sync</code></dt>
<dd>after sending each batch, emit a message and wait for that batch to finish rendering</dd>
<dt><code>tcs</code></dt>
<dd>dump shader assembly for tessellation control shaders</dd>
<dt><code>tes</code></dt>
<dd>dump shader assembly for tessellation evaluation shaders</dd>
<dt><code>tex</code></dt>
<dd>emit messages about textures.</dd>
<dt><code>urb</code></dt>
<dd>emit messages about URB setup</dd>
<dt><code>vert</code></dt>
<dd>emit messages about vertex assembly</dd>
<dt><code>vs</code></dt>
<dd>dump shader assembly for vertex shaders</dd>
</dl>
</dd>
<dt><code>INTEL_SCALAR_VS</code> (or <code>TCS</code>, <code>TES</code>,
<code>GS</code>)</dt>
<dd>force scalar/vec4 mode for a shader stage (Gen8-9 only)</dd>
<dt><code>INTEL_PRECISE_TRIG</code></dt>
<dd>if set to 1, true or yes, then the driver prefers accuracy over
performance in trig functions.</dd>
</dl>
<h2>Radeon driver environment variables (radeon, r200, and r300g)</h2>
<dl>
<dt><code>RADEON_NO_TCL</code></dt>
<dd>if set, disable hardware-accelerated Transform/Clip/Lighting.</dd>
</dl>
<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>
<dl>
<dt><code>GALLIUM_HUD</code></dt>
<dd>draws various information on the screen, like framerate,
cpu load, driver statistics, performance counters, etc.
Set <code>GALLIUM_HUD=help</code> and run e.g.
<code>glxgears</code> for more info.</dd>
<dt><code>GALLIUM_HUD_PERIOD</code></dt>
<dd>sets the hud update rate in seconds (float). Use zero
to update every frame. The default period is 1/2 second.</dd>
<dt><code>GALLIUM_HUD_VISIBLE</code></dt>
<dd>control default visibility, defaults to true.</dd>
<dt><code>GALLIUM_HUD_TOGGLE_SIGNAL</code></dt>
<dd>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
<code>GALLIUM_HUD_VISIBLE</code> to <code>false</code> and
<code>GALLIUM_HUD_TOGGLE_SIGNAL</code> to <code>10</code>
(<code>SIGUSR1</code>).
Use <code>kill -10 <pid></code> to toggle the hud as desired.</dd>
<dt><code>GALLIUM_HUD_DUMP_DIR</code></dt>
<dd>specifies a directory for writing the displayed hud values into files.</dd>
<dt><code>GALLIUM_DRIVER</code></dt>
<dd>useful in combination with <code>LIBGL_ALWAYS_SOFTWARE=true</code> for
choosing one of the software renderers <code>softpipe</code>,
<code>llvmpipe</code> or <code>swr</code>.</dd>
<dt><code>GALLIUM_LOG_FILE</code></dt>
<dd>specifies a file for logging all errors, warnings, etc.
rather than stderr.</dd>
<dt><code>GALLIUM_PRINT_OPTIONS</code></dt>
<dd>if non-zero, print all the Gallium environment variables which are
used, and their current values.</dd>
<dt><code>GALLIUM_DUMP_CPU</code></dt>
<dd>if non-zero, print information about the CPU on start-up</dd>
<dt><code>TGSI_PRINT_SANITY</code></dt>
<dd>if set, do extra sanity checking on TGSI shaders and
print any errors to stderr.</dd>
<dt><code>DRAW_FSE</code></dt>
<dd>???</dd>
<dt><code>DRAW_NO_FSE</code></dt>
<dd>???</dd>
<dt><code>DRAW_USE_LLVM</code></dt>
<dd>if set to zero, the draw module will not use LLVM to execute
shaders, vertex fetch, etc.</dd>
<dt><code>ST_DEBUG</code></dt>
<dd>controls debug output from the Mesa/Gallium state tracker.
Setting to <code>tgsi</code>, for example, will print all the TGSI
shaders. See <code>src/mesa/state_tracker/st_debug.c</code> for other
options.</dd>
</dl>
<h3>Clover state tracker environment variables</h3>
<dl>
<dt><code>CLOVER_EXTRA_BUILD_OPTIONS</code></dt>
<dd>allows specifying additional compiler and linker
options. Specified options are appended after the options set by the OpenCL
program in <code>clBuildProgram</code>.</dd>
<dt><code>CLOVER_EXTRA_COMPILE_OPTIONS</code></dt>
<dd>allows specifying additional compiler
options. Specified options are appended after the options set by the OpenCL
program in <code>clCompileProgram</code>.</dd>
<dt><code>CLOVER_EXTRA_LINK_OPTIONS</code></dt>
<dd>allows specifying additional linker
options. Specified options are appended after the options set by the OpenCL
program in <code>clLinkProgram</code>.</dd>
</dl>
<h3>Softpipe driver environment variables</h3>
<dl>
<dt><code>SOFTPIPE_DUMP_FS</code></dt>
<dd>if set, the softpipe driver will print fragment shaders to stderr</dd>
<dt><code>SOFTPIPE_DUMP_GS</code></dt>
<dd>if set, the softpipe driver will print geometry shaders to stderr</dd>
<dt><code>SOFTPIPE_NO_RAST</code></dt>
<dd>if set, rasterization is no-op'd. For profiling purposes.</dd>
<dt><code>SOFTPIPE_USE_LLVM</code></dt>
<dd>if set, the softpipe driver will try to use LLVM JIT for
vertex shading processing.</dd>
</dl>
<h3>LLVMpipe driver environment variables</h3>
<dl>
<dt><code>LP_NO_RAST</code></dt>
<dd>if set LLVMpipe will no-op rasterization</dd>
<dt><code>LP_DEBUG</code></dt>
<dd>a comma-separated list of debug options is accepted. See the
source code for details.</dd>
<dt><code>LP_PERF</code></dt>
<dd>a comma-separated list of options to selectively no-op various
parts of the driver. See the source code for details.</dd>
<dt><code>LP_NUM_THREADS</code></dt>
<dd>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.</dd>
</dl>
<h3>VMware SVGA driver environment variables</h3>
<dl>
<dt><code>SVGA_FORCE_SWTNL</code></dt>
<dd>force use of software vertex transformation</dd>
<dt><code>SVGA_NO_SWTNL</code></dt>
<dd>don't allow software vertex transformation fallbacks (will often result
in incorrect rendering).</dd>
<dt><code>SVGA_DEBUG</code></dt>
<dd>for dumping shaders, constant buffers, etc. See the code for
details.</dd>
<dt><code>SVGA_EXTRA_LOGGING</code></dt>
<dd>if set, enables extra logging to the <code>vmware.log</code> file,
such as the OpenGL program's name and command line arguments.</dd>
<dt><code>SVGA_NO_LOGGING</code></dt>
<dd>if set, disables logging to the <code>vmware.log</code> file. This is
useful when using Valgrind because it otherwise crashes when
initializing the host log feature.</dd>
</dl>
<p>See the driver code for other, lesser-used variables.</p>
<h3>WGL environment variables</h3>
<dl>
<dt><code>WGL_SWAP_INTERVAL</code></dt>
<dd>to set a swap interval, equivalent to calling
<code>wglSwapIntervalEXT()</code> in an application. If this
environment variable is set, application calls to
<code>wglSwapIntervalEXT()</code> will have no effect.</dd>
</dl>
<h3>VA-API state tracker environment variables</h3>
<dl>
<dt><code>VAAPI_MPEG4_ENABLED</code></dt>
<dd>enable MPEG4 for VA-API, disabled by default.</dd>
</dl>
<h3>VC4 driver environment variables</h3>
<dl>
<dt><code>VC4_DEBUG</code></dt>
<dd>a comma-separated list of named flags, which do various things:
<dl>
<dt><code>cl</code></dt>
<dd>dump command list during creation</dd>
<dt><code>qpu</code></dt>
<dd>dump generated QPU instructions</dd>
<dt><code>qir</code></dt>
<dd>dump QPU IR during program compile</dd>
<dt><code>nir</code></dt>
<dd>dump NIR during program compile</dd>
<dt><code>tgsi</code></dt>
<dd>dump TGSI during program compile</dd>
<dt><code>shaderdb</code></dt>
<dd>dump program compile information for shader-db analysis</dd>
<dt><code>perf</code></dt>
<dd>print during performance-related events</dd>
<dt><code>norast</code></dt>
<dd>skip actual hardware execution of commands</dd>
<dt><code>always_flush</code></dt>
<dd>flush after each draw call</dd>
<dt><code>always_sync</code></dt>
<dd>wait for finish after each flush</dd>
<dt><code>dump</code></dt>
<dd>write a GPU command stream trace file (VC4 simulator only)</dd>
</dl>
</dd>
</dl>
<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>
|
