Messages in this thread | | | Subject | Re: [PATCH v3] selftests/resctrl: Print a message if the result of MBM&CMT tests is failed on Intel cpu | From | Shuah Khan <> | Date | Tue, 8 Mar 2022 14:38:22 -0700 |
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On 3/4/22 3:39 AM, Shaopeng Tan wrote: > 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. > > Signed-off-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> > --- > Hello, > > In PATCH V2, I tried to detect whether SNC is enabled by NUMA info and > cpuinfo(socket_num), but it is not reliable and no future-proof. > > I just print a message to let users know a possible cause of "not ok", > When CMT or MBM test runs on Intel CPU, and the result is "not ok". > > This patch is based on v5.16.
Also need to be rebased on mainline latest
> > tools/testing/selftests/resctrl/resctrl_tests.c | 12 +++++++++--- > 1 file changed, 9 insertions(+), 3 deletions(-) > > diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c > index 973f09a66e1e..ec2bdce7b85f 100644 > --- a/tools/testing/selftests/resctrl/resctrl_tests.c > +++ b/tools/testing/selftests/resctrl/resctrl_tests.c > @@ -14,8 +14,9 @@ > #define BENCHMARK_ARG_SIZE 64 > > bool is_amd; > +bool is_intel; >
Why is this a global? I am not seeing a reason. These detect_*()s could be moved to resctrl.h and get rid of globals.
Instead of adding intel check to detect_amd() add detect_intel() or is_intel() and have ut return true of it detects intel.
> -void detect_amd(void) > +void detect_vendor(void) > { > FILE *inf = fopen("/proc/cpuinfo", "r"); > char *res; > @@ -29,6 +30,7 @@ void detect_amd(void) > char *s = strchr(res, ':'); > > is_amd = s && !strcmp(s, ": AuthenticAMD\n"); > + is_intel = s && !strcmp(s, ": GenuineIntel\n"); > free(res); > } > fclose(inf); > @@ -70,6 +72,8 @@ 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 (is_intel && res) > + ksft_print_msg("Intel CMT and MBM counters may be inaccurate when Sub-NUMA Clustering (SNC) is enabled. Ensure SNC is disabled in the BIOS if this system supports SNC.\n");
This message is rather long. Please make it concise.
> mbm_test_cleanup(); > } > > @@ -106,6 +110,8 @@ 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 (is_intel && res) > + ksft_print_msg("Intel CMT and MBM counters may be inaccurate when Sub-NUMA Clustering (SNC) is enabled. Ensure SNC is disabled in the BIOS if this system supports SNC.\n");
This message is rather long. Please make it concise.
> cmt_test_cleanup(); > } > > @@ -207,8 +213,8 @@ int main(int argc, char **argv) > if (geteuid() != 0) > return ksft_exit_fail_msg("Not running as root, abort testing.\n"); > > - /* Detect AMD vendor */ > - detect_amd(); > + /* Detect AMD/INTEL vendor */ > + detect_vendor(); > > if (has_ben) { > /* Extract benchmark command from command line. */ >
thanks, -- Shuah
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