linux/tools/testing/selftests/resctrl/resctrl.h, branch v6.4

selftests/resctrl: Commonize the signal handler register/unregister for all tests

2023-04-13T17:34:23Z

After creating a child process with fork() in CAT test, if a signal such as SIGINT is received, the parent process will be terminated immediately, and therefore the child process will not be killed and also resctrlfs is not unmounted. There is a signal handler registered in CMT/MBM/MBA tests, which kills child process, unmount resctrlfs, cleanups result files, etc., if a signal such as SIGINT is received. Commonize the signal handler registered for CMT/MBM/MBA tests and reuse it in CAT. To reuse the signal handler to kill child process use global bm_pid instead of local bm_pid. Also, since the MBA/MBA/CMT/CAT are run in order, unregister the signal handler at the end of each test so that the signal handler cannot be inherited by other tests. Reviewed-by: Ilpo Jarvinen Reviewed-by: Reinette Chatre Signed-off-by: Shaopeng Tan Signed-off-by: Shuah Khan

selftests/resctrl: Use remount_resctrlfs() consistently with boolean

2023-04-10T18:21:10Z

remount_resctrlfs() accepts a boolean value as an argument. Some tests pass 0/1 and some tests pass true/false. Make all the callers of remount_resctrlfs() use true/false so that the parameter usage is consistent across tests. Co-developed-by: Fenghua Yu Signed-off-by: Fenghua Yu Signed-off-by: Ilpo Järvinen Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Change name from CBM_MASK_PATH to INFO_PATH

2023-04-10T18:21:03Z

CBM_MASK_PATH is actually the path to resctrl/info. Change the macro name to correctly indicate what it represents. [ ij: Tweaked the changelog. ] Signed-off-by: Fenghua Yu Signed-off-by: Ilpo Järvinen Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Allow ->setup() to return errors

2023-04-10T18:20:41Z

resctrl_val() assumes ->setup() always returns either 0 to continue tests or < 0 in case of the normal termination of tests after x runs. The latter overlaps with normal error returns. Define END_OF_TESTS (=1) to differentiate the normal termination of tests and return errors as negative values. Alter callers of ->setup() to handle errors properly. Fixes: 790bf585b0ee ("selftests/resctrl: Add Cache Allocation Technology (CAT) selftest") Fixes: ecdbb911f22d ("selftests/resctrl: Add MBM test") Signed-off-by: Ilpo Järvinen Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Extend CPU vendor detection

2022-04-25T22:57:50Z

Currently, the resctrl_tests only has a function to detect AMD vendor. Since when the Intel Sub-NUMA Clustering feature is enabled, Intel CMT and MBM counters may not be accurate, the resctrl_tests also need a function to detect Intel vendor. And in the future, resctrl_tests will need a function to detect different vendors, such as Arm. Extend the function to detect Intel vendor as well. Also, this function can be easily extended to detect other vendors. Signed-off-by: Shaopeng Tan Reviewed-by: Reinette Chatre Reviewed-by: Shuah Khan Signed-off-by: Shuah Khan

selftests/resctrl: Use resctrl/info for feature detection

2021-04-02T19:57:57Z

Resctrl test suite before running any unit test (like cmt, cat, mbm and mba) should first check if the feature is enabled (by kernel and not just supported by H/W) on the platform or not. validate_resctrl_feature_request() is supposed to do that. This function intends to grep for relevant flags in /proc/cpuinfo but there are several issues here 1. validate_resctrl_feature_request() calls fgrep() to get flags from /proc/cpuinfo. But, fgrep() can only return a string with maximum of 255 characters and hence the complete cpu flags are never returned. 2. The substring search logic is also busted. If strstr() finds requested resctrl feature in the cpu flags, it returns pointer to the first occurrence. But, the logic negates the return value of strstr() and hence validate_resctrl_feature_request() returns false if the feature is present in the cpu flags and returns true if the feature is not present. 3. validate_resctrl_feature_request() checks if a resctrl feature is reported in /proc/cpuinfo flags or not. Having a cpu flag means that the H/W supports the feature, but it doesn't mean that the kernel enabled it. A user could selectively enable only a subset of resctrl features using kernel command line arguments. Hence, /proc/cpuinfo isn't a reliable source to check if a feature is enabled or not. The 3rd issue being the major one and fixing it requires changing the way validate_resctrl_feature_request() works. Since, /proc/cpuinfo isn't the right place to check if a resctrl feature is enabled or not, a more appropriate place is /sys/fs/resctrl/info directory. Change validate_resctrl_feature_request() such that, 1. For cat, check if /sys/fs/resctrl/info/L3 directory is present or not 2. For mba, check if /sys/fs/resctrl/info/MB directory is present or not 3. For cmt, check if /sys/fs/resctrl/info/L3_MON directory is present and check if /sys/fs/resctrl/info/L3_MON/mon_features has llc_occupancy 4. For mbm, check if /sys/fs/resctrl/info/L3_MON directory is present and check if /sys/fs/resctrl/info/L3_MON/mon_features has mbm__bytes Please note that only L3_CAT, L3_CMT, MBA and MBM are supported. CDP and L2 variants can be added later. Reported-by: Reinette Chatre Tested-by: Babu Moger Signed-off-by: Fenghua Yu Signed-off-by: Shuah Khan

selftests/resctrl: Share show_cache_info() by CAT and CMT tests

2021-04-02T19:54:14Z

show_cache_info() functions are defined separately in CAT and CMT tests. But the functions are same for the tests and unnecessary to be defined separately. Share the function by the tests. Suggested-by: Shuah Khan Tested-by: Babu Moger Signed-off-by: Fenghua Yu Signed-off-by: Shuah Khan

selftests/resctrl: Call kselftest APIs to log test results

2021-04-02T19:54:08Z

Call kselftest APIs instead of using printf() to log test results for cleaner code and better future extension. Suggested-by: Shuah Khan Tested-by: Babu Moger Signed-off-by: Fenghua Yu Signed-off-by: Shuah Khan

selftests/resctrl: Rename CQM test as CMT test

2021-04-02T19:53:54Z

CMT (Cache Monitoring Technology) [1] is a H/W feature that reports cache occupancy of a process. resctrl selftest suite has a unit test to test CMT for LLC but the test is named as CQM (Cache Quality Monitoring). Furthermore, the unit test source file is named as cqm_test.c and several functions, variables, comments, preprocessors and statements widely use "cqm" as either suffix or prefix. This rampant misusage of CQM for CMT might confuse someone who is newly looking at resctrl selftests because this feature is named CMT in the Intel Software Developer's Manual. Hence, rename all the occurrences (unit test source file name, functions, variables, comments and preprocessors) of cqm with cmt. [1] Please see Intel SDM, Volume 3, chapter 17 and section 18 for more information on CMT: https://software.intel.com/content/www/us/en/develop/articles/intel-sdm.html Suggested-by: Reinette Chatre Tested-by: Babu Moger Signed-off-by: Fenghua Yu Signed-off-by: Shuah Khan

selftests/resctrl: Clean up resctrl features check

2021-04-02T19:51:36Z

Checking resctrl features call strcmp() to compare feature strings (e.g. "mba", "cat" etc). The checkings are error prone and don't have good coding style. Define the constant strings in macros and call strncmp() to solve the potential issues. Suggested-by: Shuah Khan Tested-by: Babu Moger Signed-off-by: Fenghua Yu Signed-off-by: Shuah Khan