Environment Variables ===================== 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. LibGL environment variables --------------------------- .. envvar:: LIBGL_DEBUG If defined debug information will be printed to stderr. If set to ``verbose`` additional information will be printed. .. envvar:: LIBGL_ALWAYS_INDIRECT if set to ``true``, forces an indirect rendering context/connection. .. envvar:: LIBGL_ALWAYS_SOFTWARE if set to ``true``, always use software rendering .. envvar:: LIBGL_NO_DRAWARRAYS if set to ``true``, do not use DrawArrays GLX protocol (for debugging) .. envvar:: LIBGL_DRI2_DISABLE disable DRI2 if set to ``true``. .. envvar:: LIBGL_DRI3_DISABLE disable DRI3 if set to ``true``. .. envvar:: LIBGL_KOPPER_DISABLE disable Vulkan swapchains with Zink if set to ``true``. In general, this should not be used unless you know what you are doing. Some examples of "knowing what you are doing" include: - using a VK driver which has no WSI implementation for your display server - profiling the DRI frontend against your VK driver's WSI implementation .. envvar:: LIBGL_KOPPER_DRI2 disable DRI3 with Zink if set to ``true``. In general, this should not be used unless you know what you are doing. Some examples of "knowing what you are doing" include: - running xrdp - using a VK driver which doesn't support modifiers Core Mesa environment variables ------------------------------- .. envvar:: MESA_NO_ERROR if set to 1, error checking is disabled as per :ext:`GL_KHR_no_error`. This will result in undefined behavior for invalid use of the API, but can reduce CPU use for apps that are known to be error free. .. envvar:: 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. For release builds, :envvar:`MESA_DEBUG` defaults to off (no debug output). :envvar:`MESA_DEBUG` accepts the following comma-separated list of named flags, which adds extra behavior to just set :envvar:`MESA_DEBUG` to ``1``: ``silent`` turn off debug messages. Only useful for debug builds. ``flush`` flush after each drawing command ``incomplete_tex`` extra debug messages when a texture is incomplete ``incomplete_fbo`` extra debug messages when a FBO is incomplete ``context`` create a debug context (see ``GLX_CONTEXT_DEBUG_BIT_ARB``) and print error and performance messages to stderr (or ``MESA_LOG_FILE``). .. envvar:: MESA_PROCESS_NAME if set, overrides the process name string used internally for various purposes (e.g. for driconf option matching, logging, artifact storage, etc.). .. envvar:: MESA_LOG_FILE specifies a file name for logging all errors, warnings, etc., rather than stderr .. envvar:: 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. Note that this will override extensions override configured using driconf. .. envvar:: 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. .. envvar:: MESA_GL_VERSION_OVERRIDE changes the value returned by ``glGetString(GL_VERSION)`` and possibly the GL API type. - The format should be ``MAJOR.MINOR[FC|COMPAT]`` - ``FC`` is an optional suffix that indicates a forward compatible context. This is only valid for versions >= 3.0. - ``COMPAT`` is an optional suffix that indicates a compatibility context or :ext:`GL_ARB_compatibility` support. This is only valid for versions >= 3.1. - GL versions <= 3.0 are set to a compatibility (non-Core) profile - GL versions = 3.1, depending on the driver, it may or may not have the :ext:`GL_ARB_compatibility` extension enabled. - GL versions >= 3.2 are set to a Core profile - Examples: ``2.1`` select a compatibility (non-Core) profile with GL version 2.1. ``3.0`` select a compatibility (non-Core) profile with GL version 3.0. ``3.0FC`` select a Core+Forward Compatible profile with GL version 3.0. ``3.1`` select GL version 3.1 with :ext:`GL_ARB_compatibility` enabled per the driver default. ``3.1FC`` select GL version 3.1 with forward compatibility and :ext:`GL_ARB_compatibility` disabled. ``3.1COMPAT`` select GL version 3.1 with :ext:`GL_ARB_compatibility` enabled. ``X.Y`` override GL version to X.Y without changing the profile. ``X.YFC`` select a Core+Forward Compatible profile with GL version X.Y. ``X.YCOMPAT`` select a Compatibility profile with GL version X.Y. - Mesa may not really implement all the features of the given version. (for developers only) .. envvar:: MESA_GLES_VERSION_OVERRIDE changes the value returned by ``glGetString(GL_VERSION)`` for OpenGL ES. - The format should be ``MAJOR.MINOR`` - Examples: ``2.0``, ``3.0``, ``3.1`` - Mesa may not really implement all the features of the given version. (for developers only) .. envvar:: 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) .. envvar:: MESA_DRICONF_EXECUTABLE_OVERRIDE if set, overrides the "executable" string used specifically for driconf option matching. This takes higher precedence over more general process name override (e.g. MESA_PROCESS_NAME). .. envvar:: MESA_SHADER_CACHE_DISABLE if set to ``true``, disables the on-disk shader cache. If set to ``false``, enables the on-disk shader cache when it is disabled by default. Note that EGL_ANDROID_blob_cache is still enabled even if on-disk shader cache is disabled. .. envvar:: MESA_SHADER_CACHE_MAX_SIZE if set, determines the maximum size of the on-disk cache of compiled shader 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. .. envvar:: MESA_SHADER_CACHE_DIR if set, determines the directory to be used for the on-disk cache of compiled shader programs. If this variable is not set, then the cache will be stored in ``$XDG_CACHE_HOME/mesa_shader_cache_db`` (if that variable is set), or else within ``.cache/mesa_shader_cache_db`` within the user's home directory. .. envvar:: MESA_SHADER_CACHE_SHOW_STATS if set to ``true``, keeps hit/miss statistics for the shader cache. These statistics are printed when the app terminates. .. envvar:: MESA_DISK_CACHE_SINGLE_FILE if set to 1, enables the single file Fossilize DB on-disk shader cache implementation instead of the default Mesa-DB cache implementation. This implementation allows for loading of precompiled cache DBs via :envvar:`MESA_DISK_CACHE_READ_ONLY_FOZ_DBS` or :envvar:`MESA_DISK_CACHE_READ_ONLY_FOZ_DBS_DYNAMIC_LIST`. This implementation does not support cache size limits via :envvar:`MESA_SHADER_CACHE_MAX_SIZE`. If :envvar:`MESA_SHADER_CACHE_DIR` is not set, the cache will be stored in ``$XDG_CACHE_HOME/mesa_shader_cache_sf`` (if that variable is set) or else within ``.cache/mesa_shader_cache_sf`` within the user's home directory. .. envvar:: MESA_DISK_CACHE_MULTI_FILE if set to 1, enables the multi file on-disk shader cache implementation instead of the default Mesa-DB cache implementation. This implementation increases the overall disk usage. If :envvar:`MESA_SHADER_CACHE_DIR` is not set, the cache will be stored in ``$XDG_CACHE_HOME/mesa_shader_cache`` (if that variable is set) or else within ``.cache/mesa_shader_cache`` within the user's home directory. .. envvar:: MESA_DISK_CACHE_READ_ONLY_FOZ_DBS if set with :envvar:`MESA_DISK_CACHE_SINGLE_FILE` enabled, references a string of comma separated file paths to read only Fossilize DB shader caches for loading at initialization. The file paths are relative to the cache directory and do not include suffixes, referencing both the cache DB and its index file. E.g. ``MESA_DISK_CACHE_SINGLE_FILE=filename1`` refers to ``filename1.foz`` and ``filename1_idx.foz``. A limit of 8 DBs can be loaded and this limit is shared with :envvar:`MESA_DISK_CACHE_READ_ONLY_FOZ_DBS_DYNAMIC_LIST`. .. envvar:: MESA_DISK_CACHE_DATABASE_NUM_PARTS specifies number of mesa-db cache parts, default is 50. .. envvar:: MESA_DISK_CACHE_DATABASE_EVICTION_SCORE_2X_PERIOD Mesa-DB cache eviction algorithm calculates weighted score for the cache items. The weight is doubled based on the last access time of cache entry. By default period of weight doubling is set to one month. Period value is given in seconds. .. envvar:: MESA_DISK_CACHE_READ_ONLY_FOZ_DBS_DYNAMIC_LIST if set with :envvar:`MESA_DISK_CACHE_SINGLE_FILE` enabled, references a text file that contains a new-line separated list of read only Fossilize DB shader caches to load. The list file is modifiable at runtime to allow for loading read only caches after initialization unlike :envvar:`MESA_DISK_CACHE_READ_ONLY_FOZ_DBS`. This variable takes an absolute path to the list file. The list file must exist at initialization for updating to occur. Cache files in the list take relative paths to the current cache directory like :envvar:`MESA_DISK_CACHE_READ_ONLY_FOZ_DBS`. A limit of 8 DBs can be loaded and this limit is shared with :envvar:`MESA_DISK_CACHE_READ_ONLY_FOZ_DBS`. .. envvar:: MESA_DISK_CACHE_COMBINE_RW_WITH_RO_FOZ if set to 1, enables simultaneous use of :abbr:`RW (read-write)` and :abbr:`RW (read-write)` Fossilize DB caches. At first, data will be retrieved from the RO Fossilize cache. If data isn't found in the RO cache, then it will be retrieved from the RW cache. .. envvar:: MESA_GLSL :ref:`shading language compiler options ` .. envvar:: MESA_NO_MINMAX_CACHE when set, the minmax index cache is globally disabled. .. envvar:: MESA_SHADER_CAPTURE_PATH see :ref:`Capturing Shaders ` .. envvar:: MESA_SHADER_DUMP_PATH see :ref:`Experimenting with Shader Replacements ` .. envvar:: MESA_SHADER_READ_PATH see :ref:`Experimenting with Shader Replacements ` .. envvar:: MESA_VK_VERSION_OVERRIDE changes the Vulkan physical device version as returned in ``VkPhysicalDeviceProperties::apiVersion``. - The format should be ``MAJOR.MINOR[.PATCH]`` - This will not let you force a version higher than the driver's instance version as advertised by ``vkEnumerateInstanceVersion`` - This can be very useful for debugging but some features may not be implemented correctly. (For developers only) .. envvar:: MESA_VK_WSI_PRESENT_MODE overrides the WSI present mode clients specify in ``VkSwapchainCreateInfoKHR::presentMode``. Values can be ``fifo``, ``relaxed``, ``mailbox`` or ``immediate``. .. envvar:: MESA_VK_WSI_HEADLESS_SWAPCHAIN Forces all swapchains to be headless (no rendering will be display in the swapchain's window). .. envvar:: MESA_VK_ABORT_ON_DEVICE_LOSS causes the Vulkan driver to call abort() immediately after detecting a lost device. This is extremely useful when testing as it prevents the test suite from continuing on with a lost device. .. envvar:: MESA_VK_ENABLE_SUBMIT_THREAD for Vulkan drivers which support real timeline semaphores, this forces them to use a submit thread from the beginning, regardless of whether or not they ever see a wait-before-signal condition. .. envvar:: MESA_VK_DEVICE_SELECT_DEBUG print debug info about device selection decision-making .. envvar:: MESA_VK_TRACE A comma-separated list of trace types used for offline analysis. The option names are equal to the file extension. Traces are dumped into ``/tmp``. Captures can be triggered by pressing ``F1`` with the application window focused (Currently X11 only) or via :envvar:`MESA_VK_TRACE_FRAME` and :envvar:`MESA_VK_TRACE_TRIGGER`. .. list-table:: :header-rows: 1 * - File extension - Offline analysis tool - Supported drivers * - ``rmv`` - Radeon Memory Visualizer - ``RADV`` * - ``rgp`` - Radeon GPU Profiler - ``RADV`` * - ``rra`` - Radeon Raytracing Analyzer - ``RADV`` * - ``ctxroll`` - Context rolls - ``RADV`` - Creating RMV captures requires the ``scripts/setup.sh`` script in the Radeon Developer Tools folder to be run beforehand .. envvar:: MESA_VK_TRACE_FRAME Specifies a frame index at which a trace capture is automatically triggered. .. envvar:: MESA_VK_TRACE_TRIGGER Specifies a trigger file. Creating the file triggers the capture. (e.g. ``export MESA_VK_TRACE_TRIGGER=/tmp/trigger`` and then ``touch /tmp/trigger``) .. envvar:: MESA_LOADER_DRIVER_OVERRIDE chooses a different driver binary such as ``etnaviv`` or ``zink``. .. envvar:: DRI_PRIME_DEBUG print debug info about device selection decision-making .. envvar:: DRI_PRIME the default GPU is the one used by Wayland/Xorg or the one connected to a display. This variable allows to select a different GPU. It applies to OpenGL and Vulkan (in this case "select" means the GPU will be first in the reported physical devices list). The supported syntaxes are: - ``DRI_PRIME=N``: selects the Nth non-default GPU (N > 0). - ``DRI_PRIME=pci-0000_02_00_0``: selects the GPU connected to this PCIe bus - ``DRI_PRIME=vendor_id:device_id``: selects the first GPU matching these ids. For Vulkan it's possible to append ``!``, in which case only the selected GPU will be exposed to the application (e.g.: DRI_PRIME=1!). .. note:: ``lspci -nn | grep VGA`` can be used to know the PCIe bus or ids to use. .. envvar:: DRIRC_CONFIGDIR If set, overrides the global search-directories used when searching for drirc config files. The user-local one will still be used. Mostly useful for internal debugging. NIR passes environment variables -------------------------------- The following are only applicable for drivers that uses NIR, as they modify the behavior for the common ``NIR_PASS`` and ``NIR_PASS_V`` macros, that wrap calls to NIR lowering/optimizations. .. envvar:: NIR_DEBUG a comma-separated list of debug options to apply to NIR shaders. Use ``NIR_DEBUG=help`` to print a list of available options. .. envvar:: NIR_SKIP a comma-separated list of optimization/lowering passes to skip. Mesa Xlib driver environment variables -------------------------------------- The following are only applicable to the Mesa Xlib software driver. See the :doc:`Xlib software driver page ` for details. .. envvar:: MESA_RGB_VISUAL specifies the X visual and depth for RGB mode .. envvar:: MESA_BACK_BUFFER specifies how to implement the back color buffer, either ``pixmap`` or ``ximage`` .. envvar:: MESA_XSYNC enable synchronous X behavior (for debugging only) .. envvar:: MESA_GLX_FORCE_ALPHA if set, forces RGB windows to have an alpha channel. .. envvar:: MESA_GLX_DEPTH_BITS specifies default number of bits for depth buffer. .. envvar:: MESA_GLX_ALPHA_BITS specifies default number of bits for alpha channel. Mesa WGL driver environment variables ------------------------------------- The following are only applicable to the Mesa WGL driver, which is in use on Windows. .. envvar:: WGL_FORCE_MSAA if set to a positive value, specifies the number of MSAA samples to force when choosing the display configuration. .. envvar:: WGL_DISABLE_ERROR_DIALOGS if set to 1, true or yes, disables Win32 error dialogs. Useful for automated test-runs. Intel driver environment variables ---------------------------------------------------- .. envvar:: INTEL_BLACKHOLE_DEFAULT if set to 1, true or yes, then the OpenGL implementation will default ``GL_BLACKHOLE_RENDER_INTEL`` to true, thus disabling any rendering. .. envvar:: INTEL_DEBUG a comma-separated list of named flags, which do various things: ``ann`` annotate IR in assembly dumps ``bat`` emit batch information. Can control in which frames batches get dumped using ``INTEL_DEBUG_BATCH_FRAME_*``, where ``INTEL_DEBUG_BATCH_FRAME_START`` <= frame < ``INTEL_DEBUG_BATCH_FRAME_STOP`` ``blit`` emit messages about blit operations ``blorp`` emit messages about the blorp operations (blits & clears) ``buf`` emit messages about buffer objects ``bt`` emit messages binding tables ``capture-all`` flag all buffers to be captured by the kernel driver when generating an error stage after a GPU hang ``clip`` emit messages about the clip unit (for old gens, includes the CLIP program) ``color`` use color in output ``cs`` dump shader assembly for compute shaders ``do32`` generate compute shader SIMD32 programs even if workgroup size doesn't exceed the SIMD16 limit ``draw_bkp`` Add semaphore wait before/after draw call count. ``INTEL_DEBUG_BKP_BEFORE_DRAW_COUNT`` or ``INTEL_DEBUG_BKP_AFTER_DRAW_COUNT`` can control draw call number. To make test wait forever, we need to set preempt_timeout_ms and i915.enable_hangcheck to zero. ``fall`` emit messages about performance issues (same as ``perf``) ``fs`` dump shader assembly for fragment shaders ``gs`` dump shader assembly for geometry shaders ``heaps`` print information about the driver's heaps (ANV only) ``hex`` print instruction hex dump with the disassembly ``l3`` emit messages about the new L3 state during transitions ``mesh`` dump shader assembly for mesh shaders ``no8`` don't generate SIMD8 fragment shader ``no16`` suppress generation of 16-wide fragment shaders. useful for debugging broken shaders ``no32`` suppress generation of 32-wide fragment shaders. useful for debugging broken shaders ``no-oaconfig`` disable HW performance metric configuration, and anything related to i915-perf (useful when running on simulation) ``nocompact`` disable instruction compaction ``nodualobj`` suppress generation of dual-object geometry shader code ``nofc`` disable fast clears ``noccs`` disable lossless color compression ``optimizer`` dump shader assembly to files at each optimization pass and iteration that make progress ``pc`` emit messages about PIPE_CONTROL instruction usage ``perf`` emit messages about performance issues ``perfmon`` emit messages about :ext:`GL_AMD_performance_monitor` ``perf-symbol-names`` use performance counter symbols instead of the counter name (counter symbols are like variable names, it's sometimes easier to work with when you have lots of metrics to collect) ``reemit`` mark all state dirty on each draw call ``rt`` dump shader assembly for ray tracing shaders ``sf`` emit messages about the strips & fans unit (for old gens, includes the SF program) ``shader-print`` allow developer print traces added by `brw_nir_printf` to be printed out on the console ``soft64`` enable implementation of software 64bit floating point support ``sparse`` dump usage of sparse resources ``spill_fs`` force spilling of all registers in the scalar backend (useful to debug spilling code) ``spill_vec4`` force spilling of all registers in the vec4 backend (useful to debug spilling code) ``stall`` inserts a stall on the GPU after each draw/dispatch command to wait for it to finish before starting any new work. ``submit`` emit batchbuffer usage statistics ``sync`` after sending each batch, wait on the CPU for that batch to finish rendering ``swsb-stall`` Insert sync NOP after each instruction. This is only valid for Gfx12+. ``task`` dump shader assembly for task shaders ``tcs`` dump shader assembly for tessellation control shaders ``tcs8`` force usage of 8-patches tessellation control shaders (only for gfx 9-11) ``tes`` dump shader assembly for tessellation evaluation shaders ``tex`` emit messages about textures. ``urb`` emit messages about URB setup ``vs`` dump shader assembly for vertex shaders ``wm`` dump shader assembly for fragment shaders (same as ``fs``) ``cl-quiet`` quiets the OpenCL warnings recommending use of Intel compute-runtime .. envvar:: INTEL_DECODE a comma-separated list of enable/disable flags configuring the output produced by ``INTEL_DEBUG=bat`` (use with ``INTEL_DECODE=+color,-floats``) : ``color`` print colored output ``floats`` try to decode floating point data in buffers ``full`` print additional custom information for instructions (usually pulling more information by inspecting memory) ``offsets`` print offsets of instructions .. envvar:: INTEL_EXTENDED_METRICS By default, only a standard set of GPU metrics are advertised. This reduces time to collect metrics and hides infrequently used metrics. To enable all metrics, set value to 1. .. envvar:: INTEL_FORCE_PROBE A comma-separated list of device probe override values. The basic format is ``[,,...]``. The wildcard value of ``*`` will specify all known PCI IDs. If ``!`` precedes a PCI ID, or the wildcard value, then the device support will be disabled. All numbers are interpreted in base 16, and a ``0x`` prefix is optional. Values specified later take precedence, so the wildcard probably should only be used at the beginning. Some examples : ``1234,!abcd`` Device 0x1234 would be forced on and 0xabcd would be disabled. ``1234,!*`` All devices are disabled since the wildcard appears later. ``!*,0x1234`` All devices disabled except 0x1234 which is forced on. ``*,!0x1234`` All devices are forced on, except 0x1234 which is disabled. ``!0x1234,1234`` Support for device 0x1234 is forced on since the enable appears later. .. note:: If a device requires using :envvar:`INTEL_FORCE_PROBE` to force it to load, then Mesa does not have full support for the device. It may have limited, or possibly no functionality within Mesa at this point. It is recommended to upgrade to a Mesa which does not require :envvar:`INTEL_FORCE_PROBE` for the device as soon as it is available. .. envvar:: INTEL_MEASURE Collects GPU timestamps over common intervals, and generates a CSV report to show how long rendering took. The overhead of collection is limited to the flushing that is required at the interval boundaries for accurate timestamps. By default, timing data is sent to ``stderr``. To direct output to a file: ``INTEL_MEASURE=file=/tmp/measure.csv {workload}`` To begin capturing timestamps at a particular frame: ``INTEL_MEASURE=file=/tmp/measure.csv,start=15 {workload}`` To capture only 23 frames: ``INTEL_MEASURE=count=23 {workload}`` To capture frames 15-37, stopping before frame 38: ``INTEL_MEASURE=start=15,count=23 {workload}`` Designate an asynchronous control file with: ``INTEL_MEASURE=control=path/to/control.fifo {workload}`` As the workload runs, enable capture for 5 frames with: ``$ echo 5 > path/to/control.fifo`` Enable unbounded capture: ``$ echo -1 > path/to/control.fifo`` and disable with: ``$ echo 0 > path/to/control.fifo`` Select the boundaries of each snapshot with: ``INTEL_MEASURE=draw`` Collects timings for every render (DEFAULT) ``INTEL_MEASURE=rt`` Collects timings when the render target changes ``INTEL_MEASURE=batch`` Collects timings when batches are submitted ``INTEL_MEASURE=frame`` Collects timings at frame boundaries With ``INTEL_MEASURE=interval=5``, the duration of 5 events will be combined into a single record in the output. When possible, a single start and end event will be submitted to the GPU to minimize stalling. Combined events will not span batches, except in the case of ``INTEL_MEASURE=frame``. Collect CPU timestamps instead of GPU timestamps. Prints results immediately instead of waiting for GPU execution. Useful when used with interactive debug to know which frame, or where in frame, you are currently in. ``INTEL_MEASURE=cpu {workload}`` .. envvar:: INTEL_MODIFIER_OVERRIDE if set, determines the single DRM modifier reported back to (Vulkan) applications, in order to make selecting modifier deterministic between Vulkan driver and applications. The value can be one of the supported modifiers on a platform, but other values are also acceptable for debug purposes. .. envvar:: INTEL_NO_HW if set to 1, true or yes, prevents batches from being submitted to the hardware. This is useful for debugging hangs, etc. .. envvar:: INTEL_PRECISE_TRIG if set to 1, true or yes, then the driver prefers accuracy over performance in trig functions. .. envvar:: INTEL_SHADER_OPTIMIZER_PATH if set, determines the directory to be used for overriding shader assembly. The binaries with custom assembly should be placed in this folder and have a name formatted as ``sha1_of_assembly.bin``. The SHA-1 of a shader assembly is printed when assembly is dumped via corresponding :envvar:`INTEL_DEBUG` flag (e.g. ``vs`` for vertex shader). A binary could be generated from a dumped assembly by ``i965_asm``. For :envvar:`INTEL_SHADER_ASM_READ_PATH` to work it is necessary to enable dumping of corresponding shader stages via :envvar:`INTEL_DEBUG`. It is advised to use ``nocompact`` flag of :envvar:`INTEL_DEBUG` when dumping and overriding shader assemblies. The success of assembly override would be signified by "Successfully overrode shader with sha1 " in stderr replacing the original assembly. .. envvar:: INTEL_SHADER_ASM_READ_PATH if set, determines the directory to be used for overriding shader assembly. The binaries with custom assembly should be placed in this folder and have a name formatted as ``sha1_of_assembly.bin``. The SHA-1 of a shader assembly is printed when assembly is dumped via corresponding :envvar:`INTEL_DEBUG` flag (e.g. ``vs`` for vertex shader). A binary could be generated from a dumped assembly by ``i965_asm``. For :envvar:`INTEL_SHADER_ASM_READ_PATH` to work it is necessary to enable dumping of corresponding shader stages via :envvar:`INTEL_DEBUG`. It is advised to use ``nocompact`` flag of :envvar:`INTEL_DEBUG` when dumping and overriding shader assemblies. The success of assembly override would be signified by "Successfully overrode shader with sha1 " in stderr replacing the original assembly. .. envvar:: INTEL_SHADER_BIN_DUMP_PATH if set, determines the directory to which the compiled shaders will be dumped. They will be dumped as ``sha1_of_assembly.bin``, where the sha1 values will be the same as can be found in the :envvar:`INTEL_DEBUG` output, and can be used for :envvar:`INTEL_SHADER_ASM_READ_PATH` input. .. note:: Unlike the text form of shader dumping, :envvar:`INTEL_DEBUG` does not affect on the list of shaders to dump. All generated shaders are always dumped if :envvar:`INTEL_SHADER_BIN_DUMP_PATH` variable is set. .. envvar:: INTEL_SIMD_DEBUG a comma-separated list of named flags, which control simd dispatch widths: ``fs8`` allow generation of SIMD8 fragment shader ``fs16`` allow generation of SIMD16 fragment shader ``fs32`` allow generation of SIMD32 fragment shader ``cs8`` allow generation of SIMD8 compute shader ``cs16`` allow generation of SIMD16 compute shader ``cs32`` allow generation of SIMD32 compute shader ``ts8`` allow generation of SIMD8 task shader ``ts16`` allow generation of SIMD16 task shader ``ts32`` allow generation of SIMD32 task shader ``ms8`` allow generation of SIMD8 mesh shader ``ms16`` allow generation of SIMD16 mesh shader ``ms32`` allow generation of SIMD32 mesh shader ``rt8`` allow generation of SIMD8 ray-tracing shader ``rt16`` allow generation of SIMD16 ray-tracing shader ``rt32`` allow generation of SIMD32 ray-tracing shader If none of widths for particular shader stage was specified, then all widths are allowed. Anvil(ANV) driver environment variables --------------------------------------- .. envvar:: ANV_ENABLE_PIPELINE_CACHE If defined to ``0`` or ``false``, this will disable pipeline caching, forcing ANV to reparse and recompile any VkShaderModule (SPIRV) it is given. .. envvar:: ANV_DISABLE_SECONDARY_CMD_BUFFER_CALLS If defined to ``1`` or ``true``, this will prevent usage of self modifying command buffers to implement ``vkCmdExecuteCommands``. As a result of this, it will also disable :ext:`VK_KHR_performance_query`. .. envvar:: ANV_ALWAYS_BINDLESS If defined to ``1`` or ``true``, this forces all descriptor sets to use the internal :ref:`Bindless model`. .. envvar:: ANV_QUEUE_THREAD_DISABLE If defined to ``1`` or ``true``, this disables support for timeline semaphores. .. envvar:: ANV_USERSPACE_RELOCS If defined to ``1`` or ``true``, this forces ANV to always do kernel relocations in command buffers. This should only have an effect on hardware that doesn't support soft-pinning (Ivybridge, Haswell, Cherryview). .. envvar:: ANV_PRIMITIVE_REPLICATION_MAX_VIEWS Specifies up to how many view shaders can be lowered to handle :ext:`VK_KHR_multiview`. Beyond this number, multiview is implemented using instanced rendering. If unspecified, the value default to ``2``. .. envvar:: ANV_NO_GPL If set to 1, true, or yes, then VK_EXT_graphics_pipeline_library will be disabled. .. envvar:: ANV_SPARSE By default, the sparse resources feature is enabled. However, if set to 0, false, or no, it will be disabled. Platforms older than Tiger Lake do not support this feature. .. envvar:: ANV_SPARSE_USE_TRTT On platforms supported by Xe KMD (Lunar Lake and newer) this parameter changes the implementation of sparse resources feature. For i915 there is no option, sparse resources is always implemented with TRTT. DRI environment variables ------------------------- .. envvar:: DRI_NO_MSAA disable MSAA for GLX/EGL MSAA visuals Vulkan mesa device select layer environment variables ----------------------------------------------------- .. envvar:: MESA_VK_DEVICE_SELECT when set to "list" prints the list of devices. when set to "vid:did" number from PCI device. That PCI device is selected as default. The default device is returned as the first device in vkEnumeratePhysicalDevices API. Using "vid:did!" will have the same effect as using the ``MESA_VK_DEVICE_SELECT_FORCE_DEFAULT_DEVICE`` variable. .. envvar:: MESA_VK_DEVICE_SELECT_FORCE_DEFAULT_DEVICE when set to 1, the device identified as default will be the only one returned in vkEnumeratePhysicalDevices API. EGL environment variables ------------------------- Mesa EGL supports different sets of environment variables. See the :doc:`Mesa EGL ` page for the details. Gallium environment variables ----------------------------- .. envvar:: GALLIUM_HUD draws various information on the screen, like framerate, CPU load, driver statistics, performance counters, etc. Set :envvar:`GALLIUM_HUD` to ``help`` and run e.g. ``glxgears`` for more info. .. envvar:: GALLIUM_HUD_PERIOD sets the HUD update rate in seconds (float). Use zero to update every frame. The default period is 1/2 second. .. envvar:: GALLIUM_HUD_VISIBLE control default visibility, defaults to true. .. envvar:: GALLIUM_HUD_OPACITY control background opacity as an integer percentage (1-100), defaults to 66%. .. envvar:: 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 :envvar:`GALLIUM_HUD_VISIBLE` to ``false`` and :envvar:`GALLIUM_HUD_TOGGLE_SIGNAL` to ``10`` (``SIGUSR1``). Use ``kill -10 `` to toggle the HUD as desired. .. envvar:: GALLIUM_HUD_SCALE Scale HUD by an integer factor, for high DPI displays. Default is 1. .. envvar:: GALLIUM_HUD_ROTATION Rotate the HUD by an integer number of degrees, the specified value must be a multiple of 90. Default is 0. .. envvar:: GALLIUM_HUD_DUMP_DIR specifies a directory for writing the displayed HUD values into files. .. envvar:: GALLIUM_DRIVER useful in combination with :envvar:`LIBGL_ALWAYS_SOFTWARE` = ``true`` for choosing one of the software renderers ``softpipe`` or ``llvmpipe``. .. envvar:: GALLIUM_LOG_FILE specifies a file for logging all errors, warnings, etc. rather than stderr. .. envvar:: GALLIUM_PIPE_SEARCH_DIR specifies an alternate search directory for pipe-loader which overrides the compile-time path based on the install location. .. envvar:: GALLIUM_PRINT_OPTIONS if non-zero, print all the Gallium environment variables which are used, and their current values. .. envvar:: GALLIUM_TRACE If set, this variable will cause the :ref:`trace` output to be written to the specified file. Paths may be relative or absolute; relative paths are relative to the working directory. For example, setting it to "trace.xml" will cause the trace to be written to a file of the same name in the working directory. .. envvar:: GALLIUM_TRACE_TC If enabled while :ref:`trace` is active, this variable specifies that the threaded context should be traced for drivers which implement it. By default, the driver thread is traced, which will include any reordering of the command stream from threaded context. .. envvar:: GALLIUM_TRACE_TRIGGER If set while :ref:`trace` is active, this variable specifies a filename to monitor. Once the file exists (e.g., from the user running 'touch /path/to/file'), a single frame will be recorded into the trace output. Paths may be relative or absolute; relative paths are relative to the working directory. .. envvar:: GALLIUM_DUMP_CPU if non-zero, print information about the CPU on start-up .. envvar:: TGSI_PRINT_SANITY if set, do extra sanity checking on TGSI shaders and print any errors to stderr. .. envvar:: DRAW_FSE Enable fetch-shade-emit middle-end even though its not correct (e.g. for Softpipe) .. envvar:: DRAW_NO_FSE Disable fetch-shade-emit middle-end even when it is correct .. envvar:: DRAW_USE_LLVM if set to zero, the draw module will not use LLVM to execute shaders, vertex fetch, etc. .. envvar:: ST_DEBUG controls debug output from the Mesa/Gallium state tracker. Setting to ``tgsi``, for example, will print all the TGSI shaders. See :file:`src/mesa/state_tracker/st_debug.c` for other options. .. envvar:: GALLIUM_OVERRIDE_CPU_CAPS Override CPU capabilities for LLVMpipe and Softpipe, possible values for x86: ``nosse`` ``sse`` ``sse2`` ``sse3`` ``ssse3`` ``sse4.1`` ``avx`` Clover environment variables ---------------------------- .. envvar:: CLOVER_DEVICE_TYPE allows to overwrite the device type of devices. Possible values are ``accelerator``, ``cpu``, ``custom`` and ``gpu`` .. envvar:: CLOVER_DEVICE_VERSION_OVERRIDE overwrites the auto detected OpenCL version of a device. Possible values: ``1.0`` ``1.1`` ``1.2`` ``2.0`` ``2.1`` ``2.2`` ``3.0`` .. envvar:: CLOVER_DEVICE_CLC_VERSION_OVERRIDE overwrites the auto detected CLC version. Possible values: ``1.0`` ``1.1`` ``1.2`` ``2.0`` ``2.1`` ``2.2`` ``3.0`` .. envvar:: 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``. .. envvar:: CLOVER_EXTRA_COMPILE_OPTIONS allows specifying additional compiler options. Specified options are appended after the options set by the OpenCL program in ``clCompileProgram``. .. envvar:: CLOVER_EXTRA_LINK_OPTIONS allows specifying additional linker options. Specified options are appended after the options set by the OpenCL program in ``clLinkProgram``. .. _rusticl-env-var: .. envvar:: IRIS_ENABLE_CLOVER allows to enable experimental Clover NIR support with the iris driver if set to 1 or true. Rusticl environment variables ----------------------------- .. envvar:: RUSTICL_DEVICE_TYPE allows to overwrite the device type of devices. Possible values are ``accelerator``, ``cpu``, ``custom`` and ``gpu`` .. envvar:: RUSTICL_CL_VERSION overwrites the auto detected OpenCL version of all devices. Specified as ``major.minor``. .. envvar:: RUSTICL_ENABLE a comma-separated list of drivers to enable CL on. An optional list of comma-separated integers can be passed per driver to specify which devices to enable. Examples: - ``RUSTICL_ENABLE=iris`` (enables all iris devices) - ``RUSTICL_ENABLE=iris:1,radeonsi:0,2`` (enables second iris and first and third radeonsi device) Supported drivers (decent support with maybe a few conformance issues or bugs): ``iris``, ``llvmpipe``, ``nouveau``, ``panfrost``, ``radeonsi``, Experimental drivers (unknown level of support, expect conformance issues or major bugs): ``r600`` .. envvar:: RUSTICL_FEATURES a comma-separated list of features to enable. Those are disabled by default as they might not be stable enough or break OpenCL conformance. - ``fp16`` enables OpenCL half support - ``fp64`` enables OpenCL double support .. envvar:: RUSTICL_DEBUG a comma-separated list of debug channels to enable. - ``allow_invalid_spirv`` disables validation of any input SPIR-V - ``clc`` dumps all OpenCL C source being compiled - ``nir`` dumps nirs in various compilation stages. Might print nothing if shader caching is enabled. - ``no_reuse_context`` pipe_contexts are not recycled - ``no_variants`` disable kernel variants (e.g. specialized binaries for offsets == 0) - ``perf`` prints a warning when hitting slow paths once - ``perfspam`` same as perf, but doesn't skip same warnings - ``program`` dumps compilation logs to stderr - ``sync`` waits on the GPU to complete after every event - ``validate`` validates any internally generated SPIR-Vs, e.g. through compiling OpenCL C code .. envvar:: RUSTICL_MAX_WORK_GROUPS Limits the amount of threads per dimension in a work-group. Useful for splitting up long running tasks to increase responsiveness or to simulate the lowering of huge global sizes for testing. .. _clc-env-var: clc environment variables ----------------------------- .. envvar:: CLC_DEBUG a comma-separated list of debug channels to enable. - ``dump_llvm`` Dumps all generated LLVM IRs - ``dump_spirv`` Dumps all compiled, linked and specialized SPIR-Vs - ``verbose`` Enable debug logging of clc code Nine frontend environment variables ----------------------------------- .. envvar:: D3D_ALWAYS_SOFTWARE an integer, which forces Nine to use the CPU instead of GPU acceleration. .. envvar:: NINE_DEBUG a comma-separated list of named flags that do debugging things. Use ``NINE_DEBUG=help`` to print a list of available options. .. envvar:: NINE_FF_DUMP a boolean, which dumps shaders generated by a fixed function (FF). .. envvar:: NINE_SHADER a comma-separated list of named flags, which do alternate shader handling. Use ``NINE_SHADER=help`` to print a list of available options. .. envvar:: NINE_QUIRKS a comma-separated list of named flags that do various things. Use ``NINE_DEBUG=help`` to print a list of available options. Softpipe driver environment variables ------------------------------------- .. envvar:: SOFTPIPE_DEBUG a comma-separated list of named flags, which do various things: ``vs`` Dump vertex shader assembly to stderr ``fs`` Dump fragment shader assembly to stderr ``gs`` Dump geometry shader assembly to stderr ``cs`` Dump compute shader assembly to stderr ``no_rast`` rasterization is disabled. For profiling purposes. ``use_llvm`` the Softpipe driver will try to use LLVM JIT for vertex shading processing. LLVMpipe driver environment variables ------------------------------------- .. envvar:: LP_NO_RAST if set LLVMpipe will no-op rasterization .. envvar:: LP_DEBUG a comma-separated list of debug options is accepted. See the source code for details. .. envvar:: LP_PERF a comma-separated list of options to selectively no-op various parts of the driver. See the source code for details. .. envvar:: 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. VMware SVGA driver environment variables ---------------------------------------- .. envvar:: SVGA_FORCE_SWTNL force use of software vertex transformation .. envvar:: SVGA_NO_SWTNL don't allow software vertex transformation fallbacks (will often result in incorrect rendering). .. envvar:: SVGA_DEBUG for dumping shaders, constant buffers, etc. See the code for details. .. envvar:: SVGA_EXTRA_LOGGING if set, enables extra logging to the ``vmware.log`` file, such as the OpenGL program's name and command line arguments. .. envvar:: SVGA_NO_LOGGING if set, disables logging to the ``vmware.log`` file. This is useful when using Valgrind because it otherwise crashes when initializing the host log feature. See the driver code for other, lesser-used variables. WGL environment variables ------------------------- .. envvar:: WGL_SWAP_INTERVAL to set a swap interval, equivalent to calling ``wglSwapIntervalEXT()`` in an application. If this environment variable is set, application calls to ``wglSwapIntervalEXT()`` will have no effect. VA-API environment variables ---------------------------- .. envvar:: VAAPI_MPEG4_ENABLED enable MPEG4 for VA-API, disabled by default. VC4 driver environment variables -------------------------------- .. envvar:: VC4_DEBUG a comma-separated list of named flags, which do various things. Use ``VC4_DEBUG=help`` to print a list of available options. V3D/V3DV driver environment variables ------------------------------------- .. envvar:: V3D_DEBUG a comma-separated list of debug options. Use ``V3D_DEBUG=help`` to print a list of available options. .. _radv env-vars: RADV driver environment variables --------------------------------- .. envvar:: RADV_DEBUG a comma-separated list of named flags, which do various things: ``llvm`` enable LLVM compiler backend ``allbos`` force all allocated buffers to be referenced in submissions ``checkir`` validate the LLVM IR before LLVM compiles the shader ``epilogs`` dump fragment shader epilogs ``extra_md`` add extra information in bo metadata to help tools (umr) ``forcecompress`` Enables DCC,FMASK,CMASK,HTILE in situations where the driver supports it but normally does not deem it beneficial. ``hang`` enable GPU hangs detection and dump a report to $HOME/radv_dumps__