Re: [PATCH v7 07/13] selftests/resctrl: Add MBA test

From: Andre Przywara
Date: Fri May 10 2019 - 13:39:18 EST

On Sat, 9 Feb 2019 18:50:36 -0800
Fenghua Yu <fenghua.yu@xxxxxxxxx> wrote:

Hi,

> From: Arshiya Hayatkhan Pathan <arshiya.hayatkhan.pathan@xxxxxxxxx>
>
> MBA (Memory Bandwidth Allocation) test starts a stressful memory
> bandwidth benchmark and allocates memory bandwidth from 100% down
> to 10% for the benchmark process. For each allocation, compare
> perf IMC counter and mbm total bytes from resctrl. The difference
> between the two values should be within a threshold to pass the test.
>
> Default benchmark is built-in fill_buf. But users can specify their
> own benchmark by option "-b".
>
> We can add memory bandwidth allocation for multiple processes in the
> future.
>
> Signed-off-by: Arshiya Hayatkhan Pathan <arshiya.hayatkhan.pathan@xxxxxxxxx>
> Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@xxxxxxxxx>,
> Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
> ---
> tools/testing/selftests/resctrl/Makefile | 2 +-
> tools/testing/selftests/resctrl/mba_test.c | 177 ++++++++++++++++++++++++
> tools/testing/selftests/resctrl/resctrl.h | 2 +
> tools/testing/selftests/resctrl/resctrl_tests.c | 15 +-
> 4 files changed, 194 insertions(+), 2 deletions(-)
> create mode 100644 tools/testing/selftests/resctrl/mba_test.c
>
> diff --git a/tools/testing/selftests/resctrl/Makefile b/tools/testing/selftests/resctrl/Makefile
> index eaa8b45de10d..141cbdb619af 100644
> --- a/tools/testing/selftests/resctrl/Makefile
> +++ b/tools/testing/selftests/resctrl/Makefile
> @@ -8,7 +8,7 @@ all: resctrl_tests
>
> resctrl_tests: *.o
> $(CC) $(CFLAGS) -o resctrl_tests resctrl_tests.o resctrlfs.o \
> - resctrl_val.o fill_buf.o mbm_test.o
> + resctrl_val.o fill_buf.o mbm_test.o mba_test.o
>
> .PHONY: clean
>
> diff --git a/tools/testing/selftests/resctrl/mba_test.c b/tools/testing/selftests/resctrl/mba_test.c
> new file mode 100644
> index 000000000000..71d8feb93ac8
> --- /dev/null
> +++ b/tools/testing/selftests/resctrl/mba_test.c
> @@ -0,0 +1,177 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Memory Bandwidth Allocation (MBA) test
> + *
> + * Copyright (C) 2018 Intel Corporation
> + *
> + * Authors:
> + * Arshiya Hayatkhan Pathan <arshiya.hayatkhan.pathan@xxxxxxxxx>
> + * Sai Praneeth Prakhya <sai.praneeth.prakhya@xxxxxxxxx>,
> + * Fenghua Yu <fenghua.yu@xxxxxxxxx>
> + */
> +#include "resctrl.h"
> +
> +#define RESULT_FILE_NAME "result_mba"
> +#define NUM_OF_RUNS 5
> +#define MAX_DIFF 300

What is the unit here? MB/s?

> +#define ALLOCATION_MAX 100
> +#define ALLOCATION_MIN 10
> +#define ALLOCATION_STEP 10
> +
> +/*
> + * Change schemata percentage from 100 to 10%. Write schemata to specified
> + * con_mon grp, mon_grp in resctrl FS.
> + * For each allocation, run 5 times in order to get average values.
> + */
> +static int mba_setup(int num, ...)
> +{
> + static int runs_per_allocation, allocation = 100;
> + struct resctrl_val_param *p;
> + char allocation_str[64];
> + va_list param;
> +
> + va_start(param, num);
> + p = va_arg(param, struct resctrl_val_param *);
> + va_end(param);
> +
> + if (runs_per_allocation >= NUM_OF_RUNS)
> + runs_per_allocation = 0;
> +
> + /* Only set up schemata once every NUM_OF_RUNS of allocations */
> + if (runs_per_allocation++ != 0)
> + return 0;
> +
> + if (allocation < ALLOCATION_MIN || allocation > ALLOCATION_MAX)
> + return -1;
> +
> + sprintf(allocation_str, "%d", allocation);
> +
> + write_schemata(p->ctrlgrp, allocation_str, p->cpu_no, p->resctrl_val);
> + printf("changed schemata to : %d\n", allocation);
> + allocation -= ALLOCATION_STEP;
> +
> + return 0;
> +}
> +
> +static void show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
> +{
> + int allocation, failed = 0, runs;
> +
> + /* Memory bandwidth from 100% down to 10% */
> + for (allocation = 0; allocation < ALLOCATION_MAX / ALLOCATION_STEP;
> + allocation++) {
> + unsigned long avg_bw_imc = 0, avg_bw_resc = 0;

No need to initialise those.

> + unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
> + long avg_diff = 0;

... and this one.

> +
> + /*
> + * The first run is discarded due to inaccurate value from
> + * phase transition.
> + */
> + for (runs = NUM_OF_RUNS * allocation + 1;
> + runs < NUM_OF_RUNS * allocation + NUM_OF_RUNS ; runs++) {
> + sum_bw_imc += bw_imc[runs];
> + sum_bw_resc += bw_resc[runs];
> + }
> +
> + avg_bw_imc = sum_bw_imc / (NUM_OF_RUNS - 1);
> + avg_bw_resc = sum_bw_resc / (NUM_OF_RUNS - 1);
> + avg_diff = avg_bw_resc - avg_bw_imc;

Same comment as in the last patch: use labs() here already.

Cheers,
Andre.

> +
> + printf("\nschemata percentage: %d \t",
> + ALLOCATION_MAX - ALLOCATION_STEP * allocation);
> + printf("avg_bw_imc: %lu\t", avg_bw_imc);
> + printf("avg_bw_resc: %lu\t", avg_bw_resc);
> + printf("avg_diff: %lu\t", labs(avg_diff));
> + if (labs(avg_diff) > MAX_DIFF) {
> + printf("failed\n");
> + failed = 1;
> + } else {
> + printf("passed\n");
> + }
> + }
> +
> + if (failed) {
> + printf("\nTest for schemata change using MBA failed");
> + printf("as atleast one test failed!\n");
> + } else {
> + printf("\nTests for changing schemata using MBA passed!\n\n");
> + }
> +}
> +
> +static int check_results(void)
> +{
> + char *token_array[8], output[] = RESULT_FILE_NAME, temp[512];

The size of temp[] does not match below the usage ...

> + unsigned long bw_imc[1024], bw_resc[1024];
> + int runs;
> + FILE *fp;
> +
> + printf("\nchecking for pass/fail\n");
> + fp = fopen(output, "r");
> + if (!fp) {
> + perror("Error in opening file\n");
> +
> + return errno;
> + }
> +
> + runs = 0;
> + while (fgets(temp, 1024, fp)) {

... here. You could just use sizeof(temp) here.

> + char *token = strtok(temp, ":\t");
> + int fields = 0;
> +
> + while (token) {
> + token_array[fields++] = token;
> + token = strtok(NULL, ":\t");
> + }
> +
> + /* Field 3 is perf imc value */
> + bw_imc[runs] = strtoul(token_array[3], NULL, 0);
> + /* Field 5 is resctrl value */
> + bw_resc[runs] = strtoul(token_array[5], NULL, 0);
> + runs++;
> + }
> +
> + fclose(fp);
> +
> + show_mba_info(bw_imc, bw_resc);
> +
> + return 0;
> +}
> +
> +void mba_test_cleanup(void)
> +{
> + remove(RESULT_FILE_NAME);
> +}
> +
> +int mba_schemata_change(int cpu_no, char *bw_report, char **benchmark_cmd)
> +{
> + struct resctrl_val_param param = {
> + .resctrl_val = "mba",
> + .ctrlgrp = "c1",
> + .mongrp = "m1",
> + .cpu_no = cpu_no,
> + .mum_resctrlfs = 1,
> + .filename = RESULT_FILE_NAME,
> + .bw_report = bw_report,
> + .setup = mba_setup
> + };
> + int ret;
> +
> + remove(RESULT_FILE_NAME);
> +
> + ret = validate_resctrl_feature_request("mba");
> + if (ret)
> + return ret;
> +
> + ret = resctrl_val(benchmark_cmd, &param);
> + if (ret)
> + return ret;
> +
> + ret = check_results();
> + if (ret)
> + return ret;
> +
> + mba_test_cleanup();
> +
> + return 0;
> +}
> diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
> index 7f7ea180478c..92e5f2930c68 100644
> --- a/tools/testing/selftests/resctrl/resctrl.h
> +++ b/tools/testing/selftests/resctrl/resctrl.h
> @@ -74,5 +74,7 @@ int resctrl_val(char **benchmark_cmd, struct resctrl_val_param *param);
> int mbm_bw_change(int span, int cpu_no, char *bw_report, char **benchmark_cmd);
> void tests_cleanup(void);
> void mbm_test_cleanup(void);
> +int mba_schemata_change(int cpu_no, char *bw_report, char **benchmark_cmd);
> +void mba_test_cleanup(void);
>
> #endif /* RESCTRL_H */
> diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
> index a51780d28ff1..5fbfa8685b58 100644
> --- a/tools/testing/selftests/resctrl/resctrl_tests.c
> +++ b/tools/testing/selftests/resctrl/resctrl_tests.c
> @@ -27,6 +27,7 @@ static void cmd_help(void)
> void tests_cleanup(void)
> {
> mbm_test_cleanup();
> + mba_test_cleanup();
> }
>
> int main(int argc, char **argv)
> @@ -34,7 +35,7 @@ int main(int argc, char **argv)
> char benchmark_cmd_area[BENCHMARK_ARGS][BENCHMARK_ARG_SIZE];
> int res, c, cpu_no = 1, span = 250, argc_new = argc, i;
> int ben_ind;
> - bool has_ben = false, mbm_test = true;
> + bool has_ben = false, mbm_test = true, mba_test = true;
> char *benchmark_cmd[BENCHMARK_ARGS];
> char bw_report[64], bm_type[64];
>
> @@ -55,9 +56,12 @@ int main(int argc, char **argv)
> token = strtok(optarg, ",");
>
> mbm_test = false;
> + mba_test = false;
> while (token) {
> if (!strcmp(token, "mbm")) {
> mbm_test = true;
> + } else if (!strcmp(token, "mba")) {
> + mba_test = true;
> } else {
> printf("invalid argument\n");
>
> @@ -110,5 +114,14 @@ int main(int argc, char **argv)
> printf("Error in running tests for mbm bw change!\n");
> }
>
> + if (mba_test) {
> + printf("\nMBA Schemata Change Starting..\n");
> + if (!has_ben)
> + sprintf(benchmark_cmd[1], "%d", span);
> + res = mba_schemata_change(cpu_no, bw_report, benchmark_cmd);
> + if (res)
> + printf("Error in tests for mba-change-schemata!\n");
> + }
> +
> return 0;
> }