1.. SPDX-License-Identifier: GPL-2.0-or-later 2 3Tests setup 4=========== 5 6The internal LTP library provides a set of features that permits to customize 7tests behavior by setting environment variables and using specific tests 8arguments. 9 10Library environment variables 11----------------------------- 12 13Following environment variables are expected to be set by LTP users. Therefore, 14with some exceptions, they have ``LTP_`` prefix. Environment variables with 15``TST_`` prefix are used inside LTP shell API and should **not** be set by 16users. 17 18.. list-table:: 19 :header-rows: 1 20 21 * - Variable 22 - Note 23 24 * - KCONFIG_PATH 25 - The path to the kernel config file, (if not set, it tries the usual paths 26 ``/boot/config-RELEASE`` or ``/proc/config.gz``) 27 28 * - KCONFIG_SKIP_CHECK 29 - Skip kernel config check if variable set (not set by default) 30 31 * - LTPROOT 32 - Prefix for installed LTP. **Should be always set**, since some tests 33 need it to use data files (``LTP_DATAROOT``). LTP is by default installed 34 into ``/opt/ltp`` 35 36 * - LTP_COLORIZE_OUTPUT 37 - By default LTP colorizes it's output unless it's redirected to a pipe or 38 file. Force colorized output behavior: ``y`` or ``1``: always colorize, 39 ``n`` or ``0``: never colorize. 40 41 * - LTP_DEV 42 - Path to the block device to be used. C Language: ``.needs_device = 1``. 43 Shell language: ``TST_NEEDS_DEVICE=1``. 44 45 * - LTP_SINGLE_FS_TYPE 46 - Testing only - specifies filesystem instead all supported 47 (for tests with ``.all_filesystems``). 48 49 * - LTP_DEV_FS_TYPE 50 - Filesystem used for testing (default: ``ext2``). 51 52 * - LTP_TIMEOUT_MUL 53 - Multiplies timeout, must be number >= 0.1 (> 1 is useful for slow 54 machines to avoid unexpected timeout). 55 56 * - LTP_RUNTIME_MUL 57 - Multiplies maximal test iteration runtime. Tests that run for more than a 58 second or two are capped on runtime. You can scale the default runtime 59 both up and down with this multiplier. This is not yet implemented in the 60 shell API. 61 62 * - LTP_VIRT_OVERRIDE 63 - Overrides virtual machine detection in the test library. Setting it to 64 empty string, tells the library that system is not a virtual machine. 65 Other possible values are ``kvm``, ``xen``, ``zvm`` and ``microsoft`` 66 that describe different types supervisors. 67 68 * - PATH 69 - It's required to adjust path: ``PATH="$PATH:$LTPROOT/testcases/bin"`` 70 71 * - TMPDIR 72 - Base directory for template directory (C language: ``.needs_tmpdir = 1`` 73 and shell: ``TST_NEEDS_TMPDIR=1``). Must be an absolute path (default: 74 '/tmp'). 75 76 * - LTP_NO_CLEANUP 77 - Disable running test cleanup (defined in ``TST_CLEANUP``). 78 Shell API only. 79 80 * - LTP_ENABLE_DEBUG 81 - Enable debug info (value ``1`` or ``y``). Equivalent of ``-D`` parameter. 82 83Test execution time and timeout 84------------------------------- 85 86The limit on how long a test can run does compose of two parts: ``max_runtime`` 87and ``timeout``. The limit does apply to a single test variant. That means, for 88example, that tests which run for all available filesystems will apply this 89limit for a single filesystem only. 90 91The ``max_runtime`` is a cap on how long the ``run()`` function can take and for 92most testcases this part is set to zero. For tests that do run for more than a 93second or two the ``max_runtime`` has to be defined and the ``run()`` function 94has to check actively how much runtime is left. 95 96Test runtime can be scaled up and down with ``LTP_RUNTIME_MUL`` environment 97variable or set on a command-line by the ``-I`` parameter. However, 98setting the runtime too low will cause long running tests to exit prematurely, 99possibly before having a chance to actually test anything. 100 101The timeout is a limit for test setup and cleanup and it's also a safety 102margin for the runtime accounting. It's currently set to 30 seconds but it may 103change later. If your target machine is too slow, it can be scaled up with the 104``LTP_TIMEOUT_MUL`` environment variable. 105