From d577380da04e410a31e7f944b04d838ab1c8a1c3 Mon Sep 17 00:00:00 2001 From: Shaopeng Tan Date: Wed, 23 Mar 2022 17:09:28 +0900 Subject: selftests/resctrl: Print a message if the result of MBM&CMT tests is failed on Intel CPU According to "Intel Resource Director Technology (Intel RDT) on 2nd Generation Intel Xeon Scalable Processors Reference Manual", When the Intel Sub-NUMA Clustering(SNC) feature is enabled, Intel CMT and MBM counters may not be accurate. However, there does not seem to be an architectural way to detect if SNC is enabled. If the result of MBM&CMT test fails on Intel CPU, print a message to let users know a possible cause of failure. Acked-by: Reinette Chatre Signed-off-by: Shaopeng Tan Reviewed-by: Shuah Khan Signed-off-by: Shuah Khan --- tools/testing/selftests/resctrl/resctrl_tests.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'tools/testing/selftests/resctrl') diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c index 3e7cdf1125df..f8da3ecf67ef 100644 --- a/tools/testing/selftests/resctrl/resctrl_tests.c +++ b/tools/testing/selftests/resctrl/resctrl_tests.c @@ -86,6 +86,8 @@ static void run_mbm_test(bool has_ben, char **benchmark_cmd, int span, sprintf(benchmark_cmd[5], "%s", MBA_STR); res = mbm_bw_change(span, cpu_no, bw_report, benchmark_cmd); ksft_test_result(!res, "MBM: bw change\n"); + if ((get_vendor() == ARCH_INTEL) && res) + ksft_print_msg("Intel MBM may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n"); mbm_test_cleanup(); } @@ -122,6 +124,8 @@ static void run_cmt_test(bool has_ben, char **benchmark_cmd, int cpu_no) sprintf(benchmark_cmd[5], "%s", CMT_STR); res = cmt_resctrl_val(cpu_no, 5, benchmark_cmd); ksft_test_result(!res, "CMT: test\n"); + if ((get_vendor() == ARCH_INTEL) && res) + ksft_print_msg("Intel CMT may be inaccurate when Sub-NUMA Clustering is enabled. Check BIOS configuration.\n"); cmt_test_cleanup(); } -- cgit v1.2.3