selftests/resctrl: Replace magic constants used as array size

JIRA: https://issues.redhat.com/browse/RHEL-118965

commit a44c26d
Author: Reinette Chatre <reinette.chatre@intel.com>
Date:   Thu Oct 24 14:18:52 2024 -0700

    selftests/resctrl: Replace magic constants used as array size

    The Memory Bandwidth Allocation (MBA) test iterates through all possible
    MBA allocations, from 10% (ALLOCATION_MIN) to 100% (ALLOCATION_MAX) with
    increments of 10% (ALLOCATION_STEP) at each iteration. During each
    iteration the test measures the actual memory bandwidth NUM_OF_RUNS times
    to determine the impact of MBA on actual memory bandwidth.

    After the MBA test completes all the memory bandwidth measurements are
    parsed into an array. One array for resctrl Memory Bandwidth Monitoring
    (MBM) measurements and one array for the Integrated Memory Controller
    (iMC) measurements. Each array has a hardcoded size of 1024 that is
    large enough to hold the current test data, but this hardcoded value makes
    the implementation difficult to understand. It will not be clear that this
    array needs to be reconsidered if any of the test parameters are changed.

    Replace the magic constant as array size with the test parameters the
    array size depends on.

    Reported-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
    Closes: https://lore.kernel.org/all/45af2a8c-517d-8f0d-137d-ad0f3f6a3c68@linux.intel.com/
    Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
    Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
    Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Signed-off-by: David Arcari <darcari@redhat.com>

Author: darcari

tools/testing/selftests/resctrl/mba_test.c

@@ -127,8 +127,9 @@ static bool show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
 
 static int check_results(void)
 {
+	unsigned long bw_resc[NUM_OF_RUNS * ALLOCATION_MAX / ALLOCATION_STEP];
+	unsigned long bw_imc[NUM_OF_RUNS * ALLOCATION_MAX / ALLOCATION_STEP];
 	char *token_array[8], output[] = RESULT_FILE_NAME, temp[512];
-	unsigned long bw_imc[1024], bw_resc[1024];
 	int runs;
 	FILE *fp;