kernel/linux.git/tools/testing/selftests/resctrl/mbm_test.c, branch linux-6.9.y

selftests/resctrl: Split validate_resctrl_feature_request()

2024-02-23T22:19:15+00:00

validate_resctrl_feature_request() is used to test both if a resource is present in the info directory, and if a passed monitoring feature is present in the mon_features file. Refactor validate_resctrl_feature_request() into two smaller functions that each accomplish one check to give feature checking more granularity: - Resource directory presence in the /sys/fs/resctrl/info directory. - Feature name presence in the /sys/fs/resctrl/info//mon_features file. Signed-off-by: Maciej Wieczor-Retman Reviewed-by: Ilpo Järvinen Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Pass write_schemata() resource instead of test name

2024-02-13T20:56:45+00:00

write_schemata() takes the test name as an argument and determines the relevant resource based on the test name. Such mapping from name to resource does not really belong to resctrlfs.c that should provide only generic, test-independent functions. Pass the resource stored in the test information structure to write_schemata() instead of the test name. The new API is also more flexible as it enables to use write_schemata() for more than one resource within a test. While touching the sprintf(), move the unnecessary %c that is always '=' directly into the format string. Signed-off-by: Ilpo Järvinen Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Introduce generalized test framework

2024-02-13T20:56:45+00:00

Each test currently has a "run test" function in per test file and another resctrl_tests.c. The functions in resctrl_tests.c are almost identical. Generalize the one in resctrl_tests.c such that it can be shared between all of the tests. It makes adding new tests easier and removes the per test if () forests. Also add comment to CPU vendor IDs that they must be defined as bits for a bitmask. Signed-off-by: Ilpo Järvinen Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Create struct for input parameters

2024-02-13T20:56:45+00:00

resctrl_tests reads a set of parameters and passes them individually for each tests which causes variations in the call signature between the tests. Add struct input_params to hold all input parameters. It can be easily passed to every test without varying the call signature. Signed-off-by: Ilpo Järvinen Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Return -1 instead of errno on error

2024-02-13T20:56:43+00:00

A number of functions in the resctrl selftests return errno. It is problematic because errno is positive which is often counterintuitive. Also, every site returning errno prints the error message already with ksft_perror() so there is not much added value in returning the precise error code. Simply convert all places returning errno to return -1 that is typical userspace error code in case of failures. While at it, improve resctrl_val() comment to state that 0 means the test was run (either pass or fail). Signed-off-by: Ilpo Järvinen Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Convert perror() to ksft_perror() or ksft_print_msg()

2024-02-13T20:56:43+00:00

The resctrl selftest code contains a number of perror() calls. Some of them come with hash character and some don't. The kselftest framework provides ksft_perror() that is compatible with test output formatting so it should be used instead of adding custom hash signs. Some perror() calls are too far away from anything that sets error. For those call sites, ksft_print_msg() must be used instead. Convert perror() to ksft_perror() or ksft_print_msg(). Other related changes: - Remove hash signs - Remove trailing stops & newlines from ksft_perror() - Add terminating newlines for converted ksft_print_msg() - Use consistent capitalization - Small fixes/tweaks to typos & grammar of the messages - Extract error printing out of PARENT_EXIT() to be able to differentiate Signed-off-by: Ilpo Järvinen Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Fix MBM test failure when MBA unavailable

2023-10-18T20:33:44+00:00

Commit 20d96b25cc4c ("selftests/resctrl: Fix schemata write error check") exposed a problem in feature detection logic in MBM selftest. If schemata does not support MB:x=x entries, the schemata write to initialize 100% memory bandwidth allocation in mbm_setup() will now fail with -EINVAL due to the error handling corrected by the commit 20d96b25cc4c ("selftests/resctrl: Fix schemata write error check"). That commit just uncovers the failed write, it is not wrong itself. If MB:x=x is not supported by schemata, it is safe to assume 100% memory bandwidth is always set. Therefore, the previously ignored error does not make the MBM test itself wrong. Restore the previous behavior of MBM test by checking MB support before attempting to write it into schemata which results in behavior equivalent to ignoring the write error. Fixes: 20d96b25cc4c ("selftests/resctrl: Fix schemata write error check") Signed-off-by: Ilpo Järvinen Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Reduce failures due to outliers in MBA/MBM tests

2023-10-13T20:54:38+00:00

The initial value of 5% chosen for the maximum allowed percentage difference between resctrl mbm value and IMC mbm value in commit 06bd03a57f8c ("selftests/resctrl: Fix MBA/MBM results reporting format") was "randomly chosen value" (as admitted by the changelog). When running tests in our lab across a large number platforms, 5% difference upper bound for success seems a bit on the low side for the MBA and MBM tests. Some platforms produce outliers that are slightly above that, typically 6-7%, which leads MBA/MBM test frequently failing. Replace the "randomly chosen value" with a success bound that is based on those measurements across large number of platforms by relaxing the MBA/MBM success bound to 8%. The relaxed bound removes the failures due the frequent outliers. Fixed commit description style error during merge: Shuah Khan Fixes: 06bd03a57f8c ("selftests/resctrl: Fix MBA/MBM results reporting format") Signed-off-by: Ilpo Järvinen Tested-by: Shaopeng Tan Reviewed-by: Reinette Chatre Reviewed-by: Shaopeng Tan Cc: Signed-off-by: Shuah Khan

selftests/resctrl: Make benchmark command const and build it with pointers

2023-10-13T20:28:55+00:00

Benchmark command is used in multiple tests so it should not be mutated by the tests but CMT test alters span argument. Due to the order of tests (CMT test runs last), mutating the span argument in CMT test does not trigger any real problems currently. Mark benchmark_cmd strings as const and setup the benchmark command using pointers. Because the benchmark command becomes const, the input arguments can be used directly. Besides being simpler, using the input arguments directly also removes the internal size restriction. CMT test has to create a copy of the benchmark command before altering the benchmark command. Signed-off-by: Ilpo Järvinen Tested-by: Shaopeng Tan Reviewed-by: Shaopeng Tan Reviewed-by: Reinette Chatre Reviewed-by: "Wieczor-Retman, Maciej" Signed-off-by: Shuah Khan

selftests/resctrl: Simplify span lifetime

2023-10-13T20:28:44+00:00

struct resctrl_val_param contains span member. resctrl_val(), however, never uses it because the value of span is embedded into the default benchmark command and parsed from it by run_benchmark(). Remove span from resctrl_val_param. Provide DEFAULT_SPAN for the code that needs it. CMT and CAT tests communicate span that is different from the DEFAULT_SPAN between their internal functions which is converted into passing it directly as a parameter. Signed-off-by: Ilpo Järvinen Tested-by: Shaopeng Tan Reviewed-by: Reinette Chatre Reviewed-by: Shaopeng Tan Reviewed-by: "Wieczor-Retman, Maciej" Signed-off-by: Shuah Khan