Hi Shuah,
Could you please consider this fix for inclusion into kselftests?
Thank you very much.
Reinette
On 6/11/24 3:18 PM, Babu Moger wrote:
The non-contiguous CBM test fails on AMD with: Starting L3_NONCONT_CAT test ... Mounting resctrl to "/sys/fs/resctrl" CPUID output doesn't match 'sparse_masks' file content! not ok 5 L3_NONCONT_CAT: test
AMD always supports non-contiguous CBM but does not report it via CPUID.
Fix the non-contiguous CBM test to use CPUID to discover non-contiguous CBM support only on Intel.
Fixes: ae638551ab64 ("selftests/resctrl: Add non-contiguous CBMs CAT test") Signed-off-by: Babu Moger babu.moger@amd.com Reviewed-by: Reinette Chatre reinette.chatre@intel.com
v3: Reworked changelong.
v2: Moved the non-contiguous CBM verification to a new function arch_supports_noncont_cat.
v1: This was part of the series https://lore.kernel.org/lkml/cover.1708637563.git.babu.moger@amd.com/ Sending this as a separate fix per review comments.
tools/testing/selftests/resctrl/cat_test.c | 32 +++++++++++++++------- 1 file changed, 22 insertions(+), 10 deletions(-)
diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c index d4dffc934bc3..742782438ca3 100644 --- a/tools/testing/selftests/resctrl/cat_test.c +++ b/tools/testing/selftests/resctrl/cat_test.c @@ -288,11 +288,30 @@ static int cat_run_test(const struct resctrl_test *test, const struct user_param return ret; } +static bool arch_supports_noncont_cat(const struct resctrl_test *test) +{
- unsigned int eax, ebx, ecx, edx;
- /* AMD always supports non-contiguous CBM. */
- if (get_vendor() == ARCH_AMD)
return true;- /* Intel support for non-contiguous CBM needs to be discovered. */
- if (!strcmp(test->resource, "L3"))
__cpuid_count(0x10, 1, eax, ebx, ecx, edx);- else if (!strcmp(test->resource, "L2"))
__cpuid_count(0x10, 2, eax, ebx, ecx, edx);- else
return false;- return ((ecx >> 3) & 1);
+}
- static int noncont_cat_run_test(const struct resctrl_test *test, const struct user_params *uparams) { unsigned long full_cache_mask, cont_mask, noncont_mask;
- unsigned int eax, ebx, ecx, edx, sparse_masks;
- unsigned int sparse_masks; int bit_center, ret; char schemata[64];
@@ -301,15 +320,8 @@ static int noncont_cat_run_test(const struct resctrl_test *test, if (ret) return ret;
- if (!strcmp(test->resource, "L3"))
__cpuid_count(0x10, 1, eax, ebx, ecx, edx);- else if (!strcmp(test->resource, "L2"))
__cpuid_count(0x10, 2, eax, ebx, ecx, edx);- else
return -EINVAL;- if (sparse_masks != ((ecx >> 3) & 1)) {
ksft_print_msg("CPUID output doesn't match 'sparse_masks' file content!\n");
- if (arch_supports_noncont_cat(test) != sparse_masks) {
ksft_print_msg("Hardware and kernel differ on non-contiguous CBM support!\n");