Re: [PATCH v2 3/4] selftests/resctrl: Add support for MBM and MBA tests on AMD

Reinette Chatre
2024-05-09T21:11:56Z

Hi Babu,

On 4/25/2024 1:17 PM, Babu Moger wrote:
> Add support to read UMC (Unified Memory Controller) perf events to compare
> the numbers with QoS monitor for AMD.
>
> Signed-off-by: Babu Moger <babu.moger@amd.com>
> ---
> tools/testing/selftests/resctrl/resctrl_val.c | 67 ++++++++++++++++---
> 1 file changed, 59 insertions(+), 8 deletions(-)
>
> diff --git a/tools/testing/selftests/resctrl/resctrl_val.c b/tools/testing/selftests/resctrl/resctrl_val.c
> index e3b09128ec3d..d90d3196d7b5 100644
> --- a/tools/testing/selftests/resctrl/resctrl_val.c
> +++ b/tools/testing/selftests/resctrl/resctrl_val.c
> @@ -11,6 +11,7 @@
> #include "resctrl.h"
>
> #define UNCORE_IMC "uncore_imc"
> +#define AMD_UMC "amd_umc"
> #define READ_FILE_NAME "events/cas_count_read"
> #define WRITE_FILE_NAME "events/cas_count_write"
> #define DYN_PMU_PATH "/sys/bus/event_source/devices"
> @@ -146,6 +147,47 @@ static int open_perf_event(int i, int cpu_no, int j)
> return 0;
> }
>
> +/* Get type and config (read and write) of an UMC counter */
> +static int read_from_umc_dir(char *umc_dir, int count)
> +{
> + char umc_counter_type[PATH_MAX];
> + FILE *fp;
> +
> + /* Get type of iMC counter */

iMC counter?

> + sprintf(umc_counter_type, "%s%s", umc_dir, "type");
> + fp = fopen(umc_counter_type, "r");
> + if (!fp) {
> + ksft_perror("Failed to open imc counter type file");

Why go through effort of changing to generic names and then follow
by using Intel naming in AMD specific code?

> + return -1;
> + }
> +
> + if (fscanf(fp, "%u", &imc_counters_config[count][READ].type) <= 0) {
> + ksft_perror("Could not get imc type");

Same here.

> + fclose(fp);
> + return -1;
> + }
> +
> + fclose(fp);
> +
> + imc_counters_config[count][WRITE].type =
> + imc_counters_config[count][READ].type;
> +

Up to here seems to be a copy&paste of read_from_imc_dir(). Could you
instead split read_from_imc_dir() so that AMD and Intel can share the
code to determine type?

Reinette