linux/tools/testing/selftests/resctrl/resctrl_val.c, 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: Flush stdout file buffer before executing fork()

2023-04-13T17:34:12Z

When a process has buffered output, a child process created by fork() will also copy buffered output. When using kselftest framework, the output (resctrl test result message) will be printed multiple times. Add fflush() to flush out the buffered output before executing fork(). Reviewed-by: Shuah Khan Reviewed-by: Reinette Chatre Signed-off-by: Shaopeng Tan 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: Move ->setup() call outside of test specific branches

2023-04-10T18:20:35Z

resctrl_val() function is called only by MBM, MBA, and CMT tests which means the else branch is never used. Both test branches call param->setup(). Remove the unused else branch and place the ->setup() call outside of the test specific branches reducing code duplication. 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: Kill child process before parent process terminates if SIGTERM is received

2022-04-25T23:06:41Z

In kselftest framework, a sub test is run using the timeout utility and it will send SIGTERM to the test upon timeout. In resctrl_tests, a child process is created by fork() to run benchmark but SIGTERM is not set in sigaction(). If SIGTERM signal is received, the parent process will be killed, but the child process still exists. Kill child process before the parent process terminates if SIGTERM signal is received. Reviewed-by: Shuah Khan Reviewed-by: Reinette Chatre Reviewed-by: Fenghua Yu Signed-off-by: Shaopeng Tan Signed-off-by: Shuah Khan

selftests/resctrl: Fix checking for < 0 for unsigned values

2021-04-02T19:58:37Z

Dan reported following static checker warnings tools/testing/selftests/resctrl/resctrl_val.c:545 measure_vals() warn: 'bw_imc' unsigned <= 0 tools/testing/selftests/resctrl/resctrl_val.c:549 measure_vals() warn: 'bw_resc_end' unsigned <= 0 These warnings are reported because 1. measure_vals() declares 'bw_imc' and 'bw_resc_end' as unsigned long variables 2. Return value of get_mem_bw_imc() and get_mem_bw_resctrl() are assigned to 'bw_imc' and 'bw_resc_end' respectively 3. The returned values are checked for <= 0 to see if the calls failed Checking for < 0 for an unsigned value doesn't make any sense. Fix this issue by changing the implementation of get_mem_bw_imc() and get_mem_bw_resctrl() such that they now accept reference to a variable and set the variable appropriately upon success and return 0, else return < 0 on error. Reported-by: Dan Carpenter Tested-by: Babu Moger Signed-off-by: Fenghua Yu Signed-off-by: Shuah Khan

selftests/resctrl: Fix incorrect parsing of iMC counters

2021-04-02T19:58:31Z

iMC (Integrated Memory Controller) counters are usually at "/sys/bus/event_source/devices/" and are named as "uncore_imc_". num_of_imcs() function tries to count number of such iMC counters so that it could appropriately initialize required number of perf_attr structures that could be used to read these iMC counters. num_of_imcs() function assumes that all the directories under this path that start with "uncore_imc" are iMC counters. But, on some systems there could be directories named as "uncore_imc_free_running" which aren't iMC counters. Trying to read from such directories will result in "not found file" errors and MBM/MBA tests will fail. Hence, fix the logic in num_of_imcs() such that it looks at the first character after "uncore_imc_" to check if it's a numerical digit or not. If it's a digit then the directory represents an iMC counter, else, skip the directory. Reported-by: Reinette Chatre 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