linux/tools/testing/selftests/resctrl/resctrl_val.c, branch v6.12

selftests/resctrl: Remove test name comparing from write_bm_pid_to_resctrl()

2024-07-11T17:23:54Z

write_bm_pid_to_resctrl() uses resctrl_val to check test name which is not a good interface generic resctrl FS functions should provide. Tests define mongrp when needed. Remove the test name check in write_bm_pid_to_resctrl() to only rely on the mongrp parameter being non-NULL. Remove write_bm_pid_to_resctrl() resctrl_val parameter and resctrl_val member from the struct resctrl_val_param that are not used anymore. Similarly, remove the test name constants that are no longer used. Signed-off-by: Ilpo Järvinen Tested-by: Babu Moger Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Simplify bandwidth report type handling

2024-07-11T17:23:54Z

bw_report is only needed for selecting the correct value from the values IMC measured. It is a member in the resctrl_val_param struct and is always set to "reads". The value is then checked in resctrl_val() using validate_bw_report_request() that besides validating the input, assumes it can mutate the string which is questionable programming practice. Simplify handling bw_report: - Convert validate_bw_report_request() into get_bw_report_type() that inputs and returns const char *. Use NULL to indicate error. - Validate the report types inside measure_mem_bw(), not in resctrl_val(). - Pass bw_report to measure_mem_bw() from ->measure() hook because resctrl_val() no longer needs bw_report for anything. Signed-off-by: Ilpo Järvinen Tested-by: Babu Moger Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Add ->init() callback into resctrl_val_param

2024-07-11T17:23:54Z

The struct resctrl_val_param is there to customize behavior inside resctrl_val() which is currently not used to full extent and there are number of strcmp()s for test name in resctrl_val done by resctrl_val(). Create ->init() hook into the struct resctrl_val_param to cleanly do per test initialization. Remove also unused branches to setup paths and the related #defines for CMT test. While touching kerneldoc, make the adjacent line consistent with the newly added form (callback vs call back). Signed-off-by: Ilpo Järvinen Tested-by: Babu Moger Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Add ->measure() callback to resctrl_val_param

2024-07-11T17:23:54Z

The measurement done in resctrl_val() varies depending on test type. The decision for how to measure is decided based on the string compare to test name which is quite inflexible. Add ->measure() callback into the struct resctrl_val_param to allow each test to provide necessary code as a function which simplifies what resctrl_val() has to do. Signed-off-by: Ilpo Järvinen Tested-by: Babu Moger Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Simplify mem bandwidth file code for MBA & MBM tests

2024-07-11T17:23:54Z

initialize_mem_bw_resctrl() and set_mbm_path() contain complicated set of conditions, each yielding different file to be opened to measure memory bandwidth through resctrl FS. In practice, only two of them are used. For MBA test, ctrlgrp is always provided, and for MBM test both ctrlgrp and mongrp are set. The file used differ between MBA/MBM test, however, MBM test unnecessarily create monitor group because resctrl FS already provides monitoring interface underneath any ctrlgrp too, which is what the MBA selftest uses. Consolidate memory bandwidth file used to the one used by the MBA selftest. Remove all unused branches opening other files to simplify the code. Suggested-by: Reinette Chatre Signed-off-by: Ilpo Järvinen Tested-by: Babu Moger Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Rename measure_vals() to measure_mem_bw_vals() & document

2024-07-11T17:23:54Z

measure_vals() is awfully generic name so rename it to measure_mem_bw() to describe better what it does and document the function parameters. Signed-off-by: Ilpo Järvinen Tested-by: Babu Moger Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Cleanup bm_pid and ppid usage & limit scope

2024-07-11T17:23:54Z

'bm_pid' and 'ppid' are global variables. As they are used by different processes and in signal handler, they cannot be entirely converted into local variables. The scope of those variables can still be reduced into resctrl_val.c only. As PARENT_EXIT() macro is using 'ppid', make it a function in resctrl_val.c and pass ppid to it as an argument because it is easier to understand than using the global variable directly. Pass 'bm_pid' into measure_vals() instead of relying on the global variable which helps to make the call signatures of measure_vals() and measure_llc_resctrl() more similar to each other. Signed-off-by: Ilpo Järvinen Tested-by: Babu Moger Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Use correct type for pids

2024-07-11T17:23:53Z

A few functions receive PIDs through int arguments. PIDs variables should be of type pid_t, not int. Convert pid arguments from int to pid_t. Before printing PID, match the type to %d by casting to int which is enough for Linux (standard would allow using a longer integer type but generalizing for that would complicate the code unnecessarily, the selftest code does not need to be portable). Signed-off-by: Ilpo Järvinen Tested-by: Babu Moger Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Consolidate get_domain_id() into resctrl_val()

2024-07-11T17:23:53Z

Both initialize_mem_bw_resctrl() and initialize_llc_occu_resctrl() that are called from resctrl_val() need to determine domain ID to construct resctrl fs related paths. Both functions do it by taking CPU ID which neither needs for any other purpose than determining the domain ID. Consolidate determining the domain ID into resctrl_val() and pass the domain ID instead of CPU ID to initialize_mem_bw_resctrl() and initialize_llc_occu_resctrl(). Signed-off-by: Ilpo Järvinen Tested-by: Babu Moger Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan

selftests/resctrl: Make "bandwidth" consistent in comments & prints

2024-07-11T17:23:53Z

Resctrl selftests refer to "bandwidth" currently in two other forms in the code ("B/W" and "band width"). Use "bandwidth" consistently everywhere. While at it, fix also one "over flow" -> "overflow" on a line that is touched by the change. Suggested-by: Reinette Chatre Signed-off-by: Ilpo Järvinen Tested-by: Babu Moger Reviewed-by: Reinette Chatre Signed-off-by: Shuah Khan