docs/envvars.rst

   1 Environment Variables
   2 =====================
   3
   4 Normally, no environment variables need to be set. Most of the
   5 environment variables used by Mesa/Gallium are for debugging purposes,
   6 but they can sometimes be useful for debugging end-user issues.
   7
   8 LibGL environment variables
   9 ---------------------------
  10
  11 ``LIBGL_DEBUG``
  12    If defined debug information will be printed to stderr. If set to
  13    ``verbose`` additional information will be printed.
  14 ``LIBGL_DRIVERS_PATH``
  15    colon-separated list of paths to search for DRI drivers
  16 ``LIBGL_ALWAYS_INDIRECT``
  17    if set to ``true``, forces an indirect rendering context/connection.
  18 ``LIBGL_ALWAYS_SOFTWARE``
  19    if set to ``true``, always use software rendering
  20 ``LIBGL_NO_DRAWARRAYS``
  21    if set to ``true``, do not use DrawArrays GLX protocol (for
  22    debugging)
  23 ``LIBGL_SHOW_FPS``
  24    print framerate to stdout based on the number of ``glXSwapBuffers``
  25    calls per second.
  26 ``LIBGL_DRI3_DISABLE``
  27    disable DRI3 if set to ``true``.
  28
  29 Core Mesa environment variables
  30 -------------------------------
  31
  32 ``MESA_NO_ASM``
  33    if set, disables all assembly language optimizations
  34 ``MESA_NO_MMX``
  35    if set, disables Intel MMX optimizations
  36 ``MESA_NO_3DNOW``
  37    if set, disables AMD 3DNow! optimizations
  38 ``MESA_NO_SSE``
  39    if set, disables Intel SSE optimizations
  40 ``MESA_NO_ERROR``
  41    if set to 1, error checking is disabled as per ``KHR_no_error``. This
  42    will result in undefined behaviour for invalid use of the api, but
  43    can reduce CPU use for apps that are known to be error free.
  44 ``MESA_DEBUG``
  45    if set, error messages are printed to stderr. For example, if the
  46    application generates a ``GL_INVALID_ENUM`` error, a corresponding
  47    error message indicating where the error occurred, and possibly why,
  48    will be printed to stderr. For release builds, ``MESA_DEBUG``
  49    defaults to off (no debug output). ``MESA_DEBUG`` accepts the
  50    following comma-separated list of named flags, which adds extra
  51    behaviour to just set ``MESA_DEBUG=1``:
  52
  53    ``silent``
  54       turn off debug messages. Only useful for debug builds.
  55    ``flush``
  56       flush after each drawing command
  57    ``incomplete_tex``
  58       extra debug messages when a texture is incomplete
  59    ``incomplete_fbo``
  60       extra debug messages when a fbo is incomplete
  61    ``context``
  62       create a debug context (see ``GLX_CONTEXT_DEBUG_BIT_ARB``) and
  63       print error and performance messages to stderr (or
  64       ``MESA_LOG_FILE``).
  65
  66 ``MESA_LOG_FILE``
  67    specifies a file name for logging all errors, warnings, etc., rather
  68    than stderr
  69 ``MESA_TEX_PROG``
  70    if set, implement conventional texture env modes with fragment
  71    programs (intended for developers only)
  72 ``MESA_TNL_PROG``
  73    if set, implement conventional vertex transformation operations with
  74    vertex programs (intended for developers only). Setting this variable
  75    automatically sets the ``MESA_TEX_PROG`` variable as well.
  76 ``MESA_EXTENSION_OVERRIDE``
  77    can be used to enable/disable extensions. A value such as
  78    ``GL_EXT_foo -GL_EXT_bar`` will enable the ``GL_EXT_foo`` extension
  79    and disable the ``GL_EXT_bar`` extension.
  80 ``MESA_EXTENSION_MAX_YEAR``
  81    The ``GL_EXTENSIONS`` string returned by Mesa is sorted by extension
  82    year. If this variable is set to year X, only extensions defined on
  83    or before year X will be reported. This is to work-around a bug in
  84    some games where the extension string is copied into a fixed-size
  85    buffer without truncating. If the extension string is too long, the
  86    buffer overrun can cause the game to crash. This is a work-around for
  87    that.
  88 ``MESA_GL_VERSION_OVERRIDE``
  89    changes the value returned by ``glGetString(GL_VERSION)`` and
  90    possibly the GL API type.
  91
  92    -  The format should be ``MAJOR.MINOR[FC|COMPAT]``
  93    -  ``FC`` is an optional suffix that indicates a forward compatible
  94       context. This is only valid for versions >= 3.0.
  95    -  ``COMPAT`` is an optional suffix that indicates a compatibility
  96       context or ``GL_ARB_compatibility`` support. This is only valid
  97       for versions >= 3.1.
  98    -  GL versions <= 3.0 are set to a compatibility (non-Core) profile
  99    -  GL versions = 3.1, depending on the driver, it may or may not have
 100       the ``ARB_compatibility`` extension enabled.
 101    -  GL versions >= 3.2 are set to a Core profile
 102    -  Examples:
 103
 104       ``2.1``
 105          select a compatibility (non-Core) profile with GL version 2.1.
 106       ``3.0``
 107          select a compatibility (non-Core) profile with GL version 3.0.
 108       ``3.0FC``
 109          select a Core+Forward Compatible profile with GL version 3.0.
 110       ``3.1``
 111          select GL version 3.1 with ``GL_ARB_compatibility`` enabled per
 112          the driver default.
 113       ``3.1FC``
 114          select GL version 3.1 with forward compatibility and
 115          ``GL_ARB_compatibility`` disabled.
 116       ``3.1COMPAT``
 117          select GL version 3.1 with ``GL_ARB_compatibility`` enabled.
 118       ``X.Y``
 119          override GL version to X.Y without changing the profile.
 120       ``X.YFC``
 121          select a Core+Forward Compatible profile with GL version X.Y.
 122       ``X.YCOMPAT``
 123          select a Compatibility profile with GL version X.Y.
 124
 125    -  Mesa may not really implement all the features of the given
 126       version. (for developers only)
 127
 128 ``MESA_GLES_VERSION_OVERRIDE``
 129    changes the value returned by ``glGetString(GL_VERSION)`` for OpenGL
 130    ES.
 131
 132    -  The format should be ``MAJOR.MINOR``
 133    -  Examples: ``2.0``, ``3.0``, ``3.1``
 134    -  Mesa may not really implement all the features of the given
 135       version. (for developers only)
 136
 137 ``MESA_GLSL_VERSION_OVERRIDE``
 138    changes the value returned by
 139    ``glGetString(GL_SHADING_LANGUAGE_VERSION)``. Valid values are
 140    integers, such as ``130``. Mesa will not really implement all the
 141    features of the given language version if it's higher than what's
 142    normally reported. (for developers only)
 143 ``MESA_GLSL_CACHE_DISABLE``
 144    if set to ``true``, disables the GLSL shader cache
 145 ``MESA_GLSL_CACHE_MAX_SIZE``
 146    if set, determines the maximum size of the on-disk cache of compiled
 147    GLSL programs. Should be set to a number optionally followed by
 148    ``K``, ``M``, or ``G`` to specify a size in kilobytes, megabytes, or
 149    gigabytes. By default, gigabytes will be assumed. And if unset, a
 150    maximum size of 1GB will be used. Note: A separate cache might be
 151    created for each architecture that Mesa is installed for on your
 152    system. For example under the default settings you may end up with a
 153    1GB cache for x86_64 and another 1GB cache for i386.
 154 ``MESA_GLSL_CACHE_DIR``
 155    if set, determines the directory to be used for the on-disk cache of
 156    compiled GLSL programs. If this variable is not set, then the cache
 157    will be stored in ``$XDG_CACHE_HOME/mesa_shader_cache`` (if that
 158    variable is set), or else within ``.cache/mesa_shader_cache`` within
 159    the user's home directory.
 160 ``MESA_GLSL``
 161    `shading language compiler options <shading.html#envvars>`__
 162 ``MESA_NO_MINMAX_CACHE``
 163    when set, the minmax index cache is globally disabled.
 164 ``MESA_SHADER_CAPTURE_PATH``
 165    see `Capturing Shaders <shading.html#capture>`__
 166 ``MESA_SHADER_DUMP_PATH`` and ``MESA_SHADER_READ_PATH``
 167    see `Experimenting with Shader
 168    Replacements <shading.html#replacement>`__
 169 ``MESA_VK_VERSION_OVERRIDE``
 170    changes the Vulkan physical device version as returned in
 171    ``VkPhysicalDeviceProperties::apiVersion``.
 172
 173    -  The format should be ``MAJOR.MINOR[.PATCH]``
 174    -  This will not let you force a version higher than the driver's
 175       instance version as advertised by ``vkEnumerateInstanceVersion``
 176    -  This can be very useful for debugging but some features may not be
 177       implemented correctly. (For developers only)
 178
 179 NIR passes enviroment variables
 180 -------------------------------
 181
 182 The following are only applicable for drivers that uses NIR, as they
 183 modify the behaviour for the common NIR_PASS and NIR_PASS_V macros, that
 184 wrap calls to NIR lowering/optimizations.
 185
 186 ``NIR_PRINT``
 187    If defined, the resulting NIR shader will be printed out at each
 188    succesful NIR lowering/optimization call.
 189 ``NIR_TEST_CLONE``
 190    If defined, cloning a NIR shader would be tested at each succesful
 191    NIR lowering/optimization call.
 192 ``NIR_TEST_SERIALIZE``
 193    If defined, serialize and deserialize a NIR shader would be tested at
 194    each succesful NIR lowering/optimization call.
 195
 196 Mesa Xlib driver environment variables
 197 --------------------------------------
 198
 199 The following are only applicable to the Mesa Xlib software driver. See
 200 the `Xlib software driver page <xlibdriver.html>`__ for details.
 201
 202 ``MESA_RGB_VISUAL``
 203    specifies the X visual and depth for RGB mode
 204 ``MESA_CI_VISUAL``
 205    specifies the X visual and depth for CI mode
 206 ``MESA_BACK_BUFFER``
 207    specifies how to implement the back color buffer, either ``pixmap``
 208    or ``ximage``
 209 ``MESA_GAMMA``
 210    gamma correction coefficients for red, green, blue channels
 211 ``MESA_XSYNC``
 212    enable synchronous X behavior (for debugging only)
 213 ``MESA_GLX_FORCE_CI``
 214    if set, force GLX to treat 8bpp visuals as CI visuals
 215 ``MESA_GLX_FORCE_ALPHA``
 216    if set, forces RGB windows to have an alpha channel.
 217 ``MESA_GLX_DEPTH_BITS``
 218    specifies default number of bits for depth buffer.
 219 ``MESA_GLX_ALPHA_BITS``
 220    specifies default number of bits for alpha channel.
 221
 222 i945/i965 driver environment variables (non-Gallium)
 223 ----------------------------------------------------
 224
 225 ``INTEL_NO_HW``
 226    if set to 1, prevents batches from being submitted to the hardware.
 227    This is useful for debugging hangs, etc.
 228 ``INTEL_DEBUG``
 229    a comma-separated list of named flags, which do various things:
 230
 231    ``ann``
 232       annotate IR in assembly dumps
 233    ``aub``
 234       dump batches into an AUB trace for use with simulation tools
 235    ``bat``
 236       emit batch information
 237    ``blit``
 238       emit messages about blit operations
 239    ``blorp``
 240       emit messages about the blorp operations (blits & clears)
 241    ``buf``
 242       emit messages about buffer objects
 243    ``clip``
 244       emit messages about the clip unit (for old gens, includes the CLIP
 245       program)
 246    ``color``
 247       use color in output
 248    ``cs``
 249       dump shader assembly for compute shaders
 250    ``do32``
 251       generate compute shader SIMD32 programs even if workgroup size
 252       doesn't exceed the SIMD16 limit
 253    ``dri``
 254       emit messages about the DRI interface
 255    ``fbo``
 256       emit messages about framebuffers
 257    ``fs``
 258       dump shader assembly for fragment shaders
 259    ``gs``
 260       dump shader assembly for geometry shaders
 261    ``hex``
 262       print instruction hex dump with the disassembly
 263    ``l3``
 264       emit messages about the new L3 state during transitions
 265    ``miptree``
 266       emit messages about miptrees
 267    ``no8``
 268       don't generate SIMD8 fragment shader
 269    ``no16``
 270       suppress generation of 16-wide fragment shaders. useful for
 271       debugging broken shaders
 272    ``nocompact``
 273       disable instruction compaction
 274    ``nodualobj``
 275       suppress generation of dual-object geometry shader code
 276    ``nofc``
 277       disable fast clears
 278    ``norbc``
 279       disable single sampled render buffer compression
 280    ``optimizer``
 281       dump shader assembly to files at each optimization pass and
 282       iteration that make progress
 283    ``perf``
 284       emit messages about performance issues
 285    ``perfmon``
 286       emit messages about ``AMD_performance_monitor``
 287    ``pix``
 288       emit messages about pixel operations
 289    ``prim``
 290       emit messages about drawing primitives
 291    ``reemit``
 292       mark all state dirty on each draw call
 293    ``sf``
 294       emit messages about the strips & fans unit (for old gens, includes
 295       the SF program)
 296    ``shader_time``
 297       record how much GPU time is spent in each shader
 298    ``spill_fs``
 299       force spilling of all registers in the scalar backend (useful to
 300       debug spilling code)
 301    ``spill_vec4``
 302       force spilling of all registers in the vec4 backend (useful to
 303       debug spilling code)
 304    ``state``
 305       emit messages about state flag tracking
 306    ``submit``
 307       emit batchbuffer usage statistics
 308    ``sync``
 309       after sending each batch, emit a message and wait for that batch
 310       to finish rendering
 311    ``tcs``
 312       dump shader assembly for tessellation control shaders
 313    ``tes``
 314       dump shader assembly for tessellation evaluation shaders
 315    ``tex``
 316       emit messages about textures.
 317    ``urb``
 318       emit messages about URB setup
 319    ``vert``
 320       emit messages about vertex assembly
 321    ``vs``
 322       dump shader assembly for vertex shaders
 323
 324 ``INTEL_SCALAR_VS`` (or ``TCS``, ``TES``, ``GS``)
 325    force scalar/vec4 mode for a shader stage (Gen8-9 only)
 326 ``INTEL_PRECISE_TRIG``
 327    if set to 1, true or yes, then the driver prefers accuracy over
 328    performance in trig functions.
 329
 330 Radeon driver environment variables (radeon, r200, and r300g)
 331 -------------------------------------------------------------
 332
 333 ``RADEON_NO_TCL``
 334    if set, disable hardware-accelerated Transform/Clip/Lighting.
 335
 336 EGL environment variables
 337 -------------------------
 338
 339 Mesa EGL supports different sets of environment variables. See the `Mesa
 340 EGL <egl.html>`__ page for the details.
 341
 342 Gallium environment variables
 343 -----------------------------
 344
 345 ``GALLIUM_HUD``
 346    draws various information on the screen, like framerate, cpu load,
 347    driver statistics, performance counters, etc. Set
 348    ``GALLIUM_HUD=help`` and run e.g. ``glxgears`` for more info.
 349 ``GALLIUM_HUD_PERIOD``
 350    sets the hud update rate in seconds (float). Use zero to update every
 351    frame. The default period is 1/2 second.
 352 ``GALLIUM_HUD_VISIBLE``
 353    control default visibility, defaults to true.
 354 ``GALLIUM_HUD_TOGGLE_SIGNAL``
 355    toggle visibility via user specified signal. Especially useful to
 356    toggle hud at specific points of application and disable for
 357    unencumbered viewing the rest of the time. For example, set
 358    ``GALLIUM_HUD_VISIBLE`` to ``false`` and
 359    ``GALLIUM_HUD_TOGGLE_SIGNAL`` to ``10`` (``SIGUSR1``). Use
 360    ``kill -10 <pid>`` to toggle the hud as desired.
 361 ``GALLIUM_HUD_SCALE``
 362    Scale hud by an integer factor, for high DPI displays. Default is 1.
 363 ``GALLIUM_HUD_DUMP_DIR``
 364    specifies a directory for writing the displayed hud values into
 365    files.
 366 ``GALLIUM_DRIVER``
 367    useful in combination with ``LIBGL_ALWAYS_SOFTWARE=true`` for
 368    choosing one of the software renderers ``softpipe``, ``llvmpipe`` or
 369    ``swr``.
 370 ``GALLIUM_LOG_FILE``
 371    specifies a file for logging all errors, warnings, etc. rather than
 372    stderr.
 373 ``GALLIUM_PRINT_OPTIONS``
 374    if non-zero, print all the Gallium environment variables which are
 375    used, and their current values.
 376 ``GALLIUM_DUMP_CPU``
 377    if non-zero, print information about the CPU on start-up
 378 ``TGSI_PRINT_SANITY``
 379    if set, do extra sanity checking on TGSI shaders and print any errors
 380    to stderr.
 381 ``DRAW_FSE``
 382    ???
 383 ``DRAW_NO_FSE``
 384    ???
 385 ``DRAW_USE_LLVM``
 386    if set to zero, the draw module will not use LLVM to execute shaders,
 387    vertex fetch, etc.
 388 ``ST_DEBUG``
 389    controls debug output from the Mesa/Gallium state tracker. Setting to
 390    ``tgsi``, for example, will print all the TGSI shaders. See
 391    ``src/mesa/state_tracker/st_debug.c`` for other options.
 392
 393 Clover environment variables
 394 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 395
 396 ``CLOVER_EXTRA_BUILD_OPTIONS``
 397    allows specifying additional compiler and linker options. Specified
 398    options are appended after the options set by the OpenCL program in
 399    ``clBuildProgram``.
 400 ``CLOVER_EXTRA_COMPILE_OPTIONS``
 401    allows specifying additional compiler options. Specified options are
 402    appended after the options set by the OpenCL program in
 403    ``clCompileProgram``.
 404 ``CLOVER_EXTRA_LINK_OPTIONS``
 405    allows specifying additional linker options. Specified options are
 406    appended after the options set by the OpenCL program in
 407    ``clLinkProgram``.
 408
 409 Softpipe driver environment variables
 410 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 411
 412 ``SOFTPIPE_DUMP_FS``
 413    if set, the softpipe driver will print fragment shaders to stderr
 414 ``SOFTPIPE_DUMP_GS``
 415    if set, the softpipe driver will print geometry shaders to stderr
 416 ``SOFTPIPE_NO_RAST``
 417    if set, rasterization is no-op'd. For profiling purposes.
 418 ``SOFTPIPE_USE_LLVM``
 419    if set, the softpipe driver will try to use LLVM JIT for vertex
 420    shading processing.
 421
 422 LLVMpipe driver environment variables
 423 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 424
 425 ``LP_NO_RAST``
 426    if set LLVMpipe will no-op rasterization
 427 ``LP_DEBUG``
 428    a comma-separated list of debug options is accepted. See the source
 429    code for details.
 430 ``LP_PERF``
 431    a comma-separated list of options to selectively no-op various parts
 432    of the driver. See the source code for details.
 433 ``LP_NUM_THREADS``
 434    an integer indicating how many threads to use for rendering. Zero
 435    turns off threading completely. The default value is the number of
 436    CPU cores present.
 437
 438 VMware SVGA driver environment variables
 439 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 440
 441 ``SVGA_FORCE_SWTNL``
 442    force use of software vertex transformation
 443 ``SVGA_NO_SWTNL``
 444    don't allow software vertex transformation fallbacks (will often
 445    result in incorrect rendering).
 446 ``SVGA_DEBUG``
 447    for dumping shaders, constant buffers, etc. See the code for details.
 448 ``SVGA_EXTRA_LOGGING``
 449    if set, enables extra logging to the ``vmware.log`` file, such as the
 450    OpenGL program's name and command line arguments.
 451 ``SVGA_NO_LOGGING``
 452    if set, disables logging to the ``vmware.log`` file. This is useful
 453    when using Valgrind because it otherwise crashes when initializing
 454    the host log feature.
 455
 456 See the driver code for other, lesser-used variables.
 457
 458 WGL environment variables
 459 ~~~~~~~~~~~~~~~~~~~~~~~~~
 460
 461 ``WGL_SWAP_INTERVAL``
 462    to set a swap interval, equivalent to calling
 463    ``wglSwapIntervalEXT()`` in an application. If this environment
 464    variable is set, application calls to ``wglSwapIntervalEXT()`` will
 465    have no effect.
 466
 467 VA-API environment variables
 468 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 469
 470 ``VAAPI_MPEG4_ENABLED``
 471    enable MPEG4 for VA-API, disabled by default.
 472
 473 VC4 driver environment variables
 474 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 475
 476 ``VC4_DEBUG``
 477    a comma-separated list of named flags, which do various things:
 478
 479    ``cl``
 480       dump command list during creation
 481    ``qpu``
 482       dump generated QPU instructions
 483    ``qir``
 484       dump QPU IR during program compile
 485    ``nir``
 486       dump NIR during program compile
 487    ``tgsi``
 488       dump TGSI during program compile
 489    ``shaderdb``
 490       dump program compile information for shader-db analysis
 491    ``perf``
 492       print during performance-related events
 493    ``norast``
 494       skip actual hardware execution of commands
 495    ``always_flush``
 496       flush after each draw call
 497    ``always_sync``
 498       wait for finish after each flush
 499    ``dump``
 500       write a GPU command stream trace file (VC4 simulator only)
 501
 502 RADV driver environment variables
 503 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 504
 505 ``RADV_DEBUG``
 506    a comma-separated list of named flags, which do various things:
 507
 508    ``allbos``
 509       force all allocated buffers to be referenced in submissions
 510    ``allentrypoints``
 511       enable all device/instance entrypoints
 512    ``checkir``
 513       validate the LLVM IR before LLVM compiles the shader
 514    ``errors``
 515       display more info about errors
 516    ``info``
 517       show GPU-related information
 518    ``metashaders``
 519       dump internal meta shaders
 520    ``nobinning``
 521       disable primitive binning
 522    ``nocache``
 523       disable shaders cache
 524    ``nocompute``
 525       disable compute queue
 526    ``nodcc``
 527       disable Delta Color Compression (DCC) on images
 528    ``nodynamicbounds``
 529       do not check OOB access for dynamic descriptors
 530    ``nofastclears``
 531       disable fast color/depthstencil clears
 532    ``nohiz``
 533       disable HIZ for depthstencil images
 534    ``noibs``
 535       disable directly recording command buffers in GPU-visible memory
 536    ``noloadstoreopt``
 537       disable LLVM SILoadStoreOptimizer pass
 538    ``nomemorycache``
 539       disable memory shaders cache
 540    ``nongg``
 541       disable NGG for GFX10+
 542    ``nooutoforder``
 543       disable out-of-order rasterization
 544    ``noshaderballot``
 545       disable shader ballot
 546    ``nothreadllvm``
 547       disable LLVM threaded compilation
 548    ``preoptir``
 549       dump LLVM IR before any optimizations
 550    ``shaders``
 551       dump shaders
 552    ``shaderstats``
 553       dump shader statistics
 554    ``spirv``
 555       dump SPIR-V
 556    ``startup``
 557       display info at startup
 558    ``syncshaders``
 559       synchronize shaders after all draws/dispatches
 560    ``vmfaults``
 561       check for VM memory faults via dmesg
 562    ``zerovram``
 563       initialize all memory allocated in VRAM as zero
 564
 565 ``RADV_FORCE_FAMILY``
 566    create a null device to compile shaders without a AMD GPU (eg.
 567    gfx900)
 568 ``RADV_PERFTEST``
 569    a comma-separated list of named flags, which do various things:
 570
 571    ``aco``
 572       enable ACO experimental compiler
 573    ``bolist``
 574       enable the global BO list
 575    ``cswave32``
 576       enable wave32 for compute shaders (GFX10+)
 577    ``dccmsaa``
 578       enable DCC for MSAA images
 579    ``dfsm``
 580       enable dfsm
 581    ``gewave32``
 582       enable wave32 for vertex/tess/geometry shaders (GFX10+)
 583    ``localbos``
 584       enable local BOs
 585    ``pswave32``
 586       enable wave32 for pixel shaders (GFX10+)
 587    ``shader_ballot``
 588       enable shader ballot
 589    ``tccompatcmask``
 590       enable TC-compat cmask for MSAA images
 591
 592 ``RADV_SECURE_COMPILE_THREADS``
 593    maximum number of secure compile threads (up to 32)
 594 ``RADV_TEX_ANISO``
 595    force anisotropy filter (up to 16)
 596 ``RADV_TRACE_FILE``
 597    generate cmdbuffer tracefiles when a GPU hang is detected
 598 ``ACO_DEBUG``
 599    a comma-separated list of named flags, which do various things:
 600
 601    ``validateir``
 602       validate the ACO IR at various points of compilation (enabled by
 603       default for debug/debugoptimized builds)
 604    ``validatera``
 605       validate register assignment of ACO IR and catches many RA bugs
 606    ``perfwarn``
 607       abort on some suboptimal code generation
 608
 609 radeonsi driver environment variables
 610 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 611
 612 ``AMD_DEBUG``
 613    a comma-separated list of named flags, which do various things:
 614 ``nodma``
 615    Disable SDMA
 616 ``nodmaclear``
 617    Disable SDMA clears
 618 ``nodmacopyimage``
 619    Disable SDMA image copies
 620 ``zerovram``
 621    Clear VRAM allocations.
 622 ``nodcc``
 623    Disable DCC.
 624 ``nodccclear``
 625    Disable DCC fast clear.
 626 ``nodccfb``
 627    Disable separate DCC on the main framebuffer
 628 ``nodccmsaa``
 629    Disable DCC for MSAA
 630 ``nodpbb``
 631    Disable DPBB.
 632 ``nodfsm``
 633    Disable DFSM.
 634 ``notiling``
 635    Disable tiling
 636 ``nofmask``
 637    Disable MSAA compression
 638 ``nohyperz``
 639    Disable Hyper-Z
 640 ``norbplus``
 641    Disable RB+.
 642 ``no2d``
 643    Disable 2D tiling
 644 ``info``
 645    Print driver information
 646 ``tex``
 647    Print texture info
 648 ``compute``
 649    Print compute info
 650 ``vm``
 651    Print virtual addresses when creating resources
 652 ``vs``
 653    Print vertex shaders
 654 ``ps``
 655    Print pixel shaders
 656 ``gs``
 657    Print geometry shaders
 658 ``tcs``
 659    Print tessellation control shaders
 660 ``tes``
 661    Print tessellation evaluation shaders
 662 ``cs``
 663    Print compute shaders
 664 ``noir``
 665    Don't print the LLVM IR
 666 ``nonir``
 667    Don't print NIR when printing shaders
 668 ``noasm``
 669    Don't print disassembled shaders
 670 ``preoptir``
 671    Print the LLVM IR before initial optimizations
 672 ``gisel``
 673    Enable LLVM global instruction selector.
 674 ``w32ge``
 675    Use Wave32 for vertex, tessellation, and geometry shaders.
 676 ``w32ps``
 677    Use Wave32 for pixel shaders.
 678 ``w32cs``
 679    Use Wave32 for computes shaders.
 680 ``w64ge``
 681    Use Wave64 for vertex, tessellation, and geometry shaders.
 682 ``w64ps``
 683    Use Wave64 for pixel shaders.
 684 ``w64cs``
 685    Use Wave64 for computes shaders.
 686 ``checkir``
 687    Enable additional sanity checks on shader IR
 688 ``mono``
 689    Use old-style monolithic shaders compiled on demand
 690 ``nooptvariant``
 691    Disable compiling optimized shader variants.
 692 ``forcedma``
 693    Use SDMA for all operations when possible.
 694 ``nowc``
 695    Disable GTT write combining
 696 ``check_vm``
 697    Check VM faults and dump debug info.
 698 ``reserve_vmid``
 699    Force VMID reservation per context.
 700 ``nogfx``
 701    Disable graphics. Only multimedia compute paths can be used.
 702 ``nongg``
 703    Disable NGG and use the legacy pipeline.
 704 ``nggc``
 705    Always use NGG culling even when it can hurt.
 706 ``nonggc``
 707    Disable NGG culling.
 708 ``alwayspd``
 709    Always enable the primitive discard compute shader.
 710 ``pd``
 711    Enable the primitive discard compute shader for large draw calls.
 712 ``nopd``
 713    Disable the primitive discard compute shader.
 714 ``switch_on_eop``
 715    Program WD/IA to switch on end-of-packet.
 716 ``nooutoforder``
 717    Disable out-of-order rasterization
 718 ``dpbb``
 719    Enable DPBB.
 720 ``dfsm``
 721    Enable DFSM.
 722
 723 Other Gallium drivers have their own environment variables. These may
 724 change frequently so the source code should be consulted for details.