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

commit ef43c30858754d99373a63dff33280a9969b49bc upstream.

The initial value of 5% chosen for the maximum allowed percentage
difference between resctrl mbm value and IMC mbm value in

commit 06bd03a57f ("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 <skhan@linuxfoundation.org>

Fixes: 06bd03a57f ("selftests/resctrl: Fix MBA/MBM results reporting format")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ilpo Järvinen 2023-10-02 12:48:13 +03:00 committed by Greg Kroah-Hartman
parent a8eba04777
commit 7fb9d792c0
2 changed files with 2 additions and 2 deletions

View File

@ -12,7 +12,7 @@
#define RESULT_FILE_NAME "result_mba"
#define NUM_OF_RUNS 5
#define MAX_DIFF_PERCENT 5
#define MAX_DIFF_PERCENT 8
#define ALLOCATION_MAX 100
#define ALLOCATION_MIN 10
#define ALLOCATION_STEP 10

View File

@ -11,7 +11,7 @@
#include "resctrl.h"
#define RESULT_FILE_NAME "result_mbm"
#define MAX_DIFF_PERCENT 5
#define MAX_DIFF_PERCENT 8
#define NUM_OF_RUNS 5
static int