Re: [PATCH v7 09/13] selftests/resctrl: Add Cache Allocation Technology (CAT) selftest

From: Andre Przywara
Date: Fri May 10 2019 - 13:40:18 EST

On Sat, 9 Feb 2019 18:50:38 -0800
Fenghua Yu <fenghua.yu@xxxxxxxxx> wrote:

Hi,

> From: Arshiya Hayatkhan Pathan <arshiya.hayatkhan.pathan@xxxxxxxxx>
>
> Cache Allocation Technology (CAT) selftest allocates a portion of
> last level cache and starts a benchmark to read each cache
> line in this portion of cache. Measure the cache misses in perf and
> the misses should be equal to the number of cache lines in this
> portion of cache.
>
> We don't use CQM to calculate cache usage because some CAT enabled
> platforms don't have CQM.
>
> 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/cache.c | 175 ++++++++++++++++-
> tools/testing/selftests/resctrl/cat_test.c | 242 ++++++++++++++++++++++++
> tools/testing/selftests/resctrl/fill_buf.c | 10 +-
> tools/testing/selftests/resctrl/resctrl.h | 3 +
> tools/testing/selftests/resctrl/resctrl_tests.c | 14 +-
> tools/testing/selftests/resctrl/resctrlfs.c | 10 +-
> 7 files changed, 448 insertions(+), 8 deletions(-)
> create mode 100644 tools/testing/selftests/resctrl/cat_test.c
>
> diff --git a/tools/testing/selftests/resctrl/Makefile b/tools/testing/selftests/resctrl/Makefile
> index 664561cd76e6..0282222b4c22 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 mba_test.o cache.o cqm_test.o
> + resctrl_val.o fill_buf.o mbm_test.o mba_test.o cache.o cqm_test.o cat_test.o
>
> .PHONY: clean
>
> diff --git a/tools/testing/selftests/resctrl/cache.c b/tools/testing/selftests/resctrl/cache.c
> index 876dc647b3ca..04b7aafdb409 100644
> --- a/tools/testing/selftests/resctrl/cache.c
> +++ b/tools/testing/selftests/resctrl/cache.c
> @@ -10,10 +10,107 @@ struct read_format {
> } values[2];
> };
>
> +static struct perf_event_attr pea_llc_miss;
> +static struct read_format rf_cqm;
> +static int fd_lm;
> char cbm_mask[256];
> unsigned long long_mask;
> char llc_occup_path[1024];
>
> +static void initialize_perf_event_attr(void)
> +{
> + pea_llc_miss.type = PERF_TYPE_HARDWARE;
> + pea_llc_miss.size = sizeof(struct perf_event_attr);
> + pea_llc_miss.read_format = PERF_FORMAT_GROUP;
> + pea_llc_miss.exclude_kernel = 1;
> + pea_llc_miss.exclude_hv = 1;
> + pea_llc_miss.exclude_idle = 1;
> + pea_llc_miss.exclude_callchain_kernel = 1;
> + pea_llc_miss.inherit = 1;
> + pea_llc_miss.exclude_guest = 1;
> + pea_llc_miss.disabled = 1;
> +}
> +
> +static void ioctl_perf_event_ioc_reset_enable(void)
> +{
> + ioctl(fd_lm, PERF_EVENT_IOC_RESET, 0);
> + ioctl(fd_lm, PERF_EVENT_IOC_ENABLE, 0);
> +}
> +
> +static int perf_event_open_llc_miss(pid_t pid, int cpu_no)
> +{
> + fd_lm = perf_event_open(&pea_llc_miss, pid, cpu_no, -1,
> + PERF_FLAG_FD_CLOEXEC);
> + if (fd_lm == -1) {
> + perror("Error opening leader");
> + ctrlc_handler(0, NULL, NULL);
> + return -1;
> + }
> +
> + return 0;
> +}
> +
> +static int initialize_llc_perf(void)
> +{
> + memset(&pea_llc_miss, 0, sizeof(struct perf_event_attr));
> + memset(&rf_cqm, 0, sizeof(struct read_format));
> +
> + /* Initialize perf_event_attr structures for HW_CACHE_MISSES */
> + initialize_perf_event_attr();
> +
> + pea_llc_miss.config = PERF_COUNT_HW_CACHE_MISSES;
> +
> + rf_cqm.nr = 1;
> +
> + return 0;
> +}
> +
> +static int reset_enable_llc_perf(pid_t pid, int cpu_no)
> +{
> + int ret = 0;
> +
> + ret = perf_event_open_llc_miss(pid, cpu_no);
> + if (ret < 0)
> + return ret;
> +
> + /* Start counters to log values */
> + ioctl_perf_event_ioc_reset_enable();
> +
> + return 0;
> +}
> +
> +/*
> + * get_llc_perf: llc cache miss through perf events
> + * @cpu_no: CPU number that the benchmark PID is binded to
> + *
> + * Perf events like HW_CACHE_MISSES could be used to validate number of
> + * cache lines allocated.
> + *
> + * Return: =0 on success. <0 on failure.
> + */
> +static int get_llc_perf(unsigned long *llc_perf_miss)
> +{
> + __u64 total_misses;
> +
> + /* Stop counters after one span to get miss rate */
> +
> + ioctl(fd_lm, PERF_EVENT_IOC_DISABLE, 0);
> +
> + if (read(fd_lm, &rf_cqm, sizeof(struct read_format)) == -1) {
> + perror("Could not get llc misses through perf");
> +
> + return -1;
> + }
> +
> + total_misses = rf_cqm.values[0].value;
> +
> + close(fd_lm);
> +
> + *llc_perf_miss = total_misses;
> +
> + return 0;
> +}
> +
> /*
> * Get LLC Occupancy as reported by RESCTRL FS
> * For CQM,
> @@ -81,10 +178,20 @@ static int print_results_cache(char *filename, int bm_pid,
>
> int measure_cache_vals(struct resctrl_val_param *param, int bm_pid)
> {
> - unsigned long llc_occu_resc = 0, llc_value = 0;
> + unsigned long llc_perf_miss = 0, llc_occu_resc = 0, llc_value = 0;
> int ret;
>
> /*
> + * Measure cache miss from perf.
> + */
> + if (!strcmp(param->resctrl_val, "cat")) {
> + ret = get_llc_perf(&llc_perf_miss);
> + if (ret < 0)
> + return ret;
> + llc_value = llc_perf_miss;
> + }
> +
> + /*
> * Measure llc occupancy from resctrl.
> */
> if (!strcmp(param->resctrl_val, "cqm")) {
> @@ -99,3 +206,69 @@ int measure_cache_vals(struct resctrl_val_param *param, int bm_pid)
>
> return 0;
> }
> +
> +/*
> + * cache_val: execute benchmark and measure LLC occupancy resctrl
> + * and perf cache miss for the benchmark
> + * @param: parameters passed to cache_val()
> + *
> + * Return: 0 on success. non-zero on failure.
> + */
> +int cat_val(struct resctrl_val_param *param)
> +{
> + int malloc_and_init_memory = 1, memflush = 1, operation = 0, ret = 0;
> + char *resctrl_val = param->resctrl_val;
> + pid_t bm_pid;
> +
> + if (strcmp(param->filename, "") == 0)
> + sprintf(param->filename, "stdio");
> +
> + bm_pid = getpid();
> +
> + /* Taskset benchmark to specified cpu */
> + ret = taskset_benchmark(bm_pid, param->cpu_no);
> + if (ret)
> + return ret;
> +
> + /* Write benchmark to specified con_mon grp, mon_grp in resctrl FS*/
> + ret = write_bm_pid_to_resctrl(bm_pid, param->ctrlgrp, param->mongrp,
> + resctrl_val);
> + if (ret)
> + return ret;
> +
> + if ((strcmp(resctrl_val, "cat") == 0)) {
> + ret = initialize_llc_perf();
> + if (ret)
> + return ret;
> + }
> +
> + /* Test runs until the callback setup() tells the test to stop. */
> + while (1) {
> + if (strcmp(resctrl_val, "cat") == 0) {
> + ret = param->setup(1, param);
> + if (ret) {
> + ret = 0;
> + break;
> + }
> + ret = reset_enable_llc_perf(bm_pid, param->cpu_no);
> + if (ret)
> + break;
> +
> + if (run_fill_buf(param->span, malloc_and_init_memory,
> + memflush, operation, resctrl_val)) {
> + fprintf(stderr, "Error-running fill buffer\n");
> + ret = -1;
> + break;
> + }
> +
> + sleep(1);
> + ret = measure_cache_vals(param, bm_pid);
> + if (ret)
> + break;
> + } else {
> + break;
> + }
> + }
> +
> + return ret;
> +}
> diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c
> new file mode 100644
> index 000000000000..1a0f77e4f7bf
> --- /dev/null
> +++ b/tools/testing/selftests/resctrl/cat_test.c
> @@ -0,0 +1,242 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Cache Allocation Technology (CAT) 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"
> +#include <unistd.h>
> +
> +#define RESULT_FILE_NAME1 "result_cat1"
> +#define RESULT_FILE_NAME2 "result_cat2"
> +#define NUM_OF_RUNS 5
> +#define MAX_DIFF_PERCENT 4
> +#define MAX_DIFF 1000000
> +
> +int count_of_bits;
> +char cbm_mask[256];
> +unsigned long long_mask;
> +unsigned long cache_size;
> +
> +/*
> + * Change schemata. Write schemata to specified
> + * con_mon grp, mon_grp in resctrl FS.
> + * Run 5 times in order to get average values.
> + */
> +static int cat_setup(int num, ...)
> +{
> + struct resctrl_val_param *p;
> + char schemata[64];
> + va_list param;
> + int ret = 0;
> +
> + va_start(param, num);
> + p = va_arg(param, struct resctrl_val_param *);
> + va_end(param);
> +
> + /* Run NUM_OF_RUNS times */
> + if (p->num_of_runs >= NUM_OF_RUNS)
> + return -1;
> +
> + if (p->num_of_runs == 0) {
> + sprintf(schemata, "%lx", p->mask);
> + ret = write_schemata(p->ctrlgrp, schemata, p->cpu_no,
> + p->resctrl_val);
> + }
> + p->num_of_runs++;
> +
> + return ret;
> +}
> +
> +static void show_cache_info(unsigned long sum_llc_perf_miss, int no_of_bits,
> + unsigned long span)
> +{
> + unsigned long allocated_cache_lines = span / 64;
> + unsigned long avg_llc_perf_miss = 0;

No need to initialise.

> + float diff_percent;

Please not floats for no reason. Should be an int, saves you some nasty
casts below.

> +
> + avg_llc_perf_miss = sum_llc_perf_miss / (NUM_OF_RUNS - 1);
> + diff_percent = ((float)allocated_cache_lines - avg_llc_perf_miss) /
> + allocated_cache_lines * 100;

That looks confusing. Shouldn't it be:

diff_percent = avg_llc_perf_miss * 100 / allocated_cache_lines;

Otherwise I have a hard time to see how this matches the check below.

> + printf("Results are displayed in (Bytes)\n");
> + printf("\nNumber of bits: %d \t", no_of_bits);
> + printf("Avg_llc_perf_miss: %lu \t", avg_llc_perf_miss);
> + printf("Allocated cache lines: %lu \t", allocated_cache_lines);
> + printf("Percent diff=%d \t", abs((int)diff_percent));
> +
> + if (abs((int)diff_percent) > MAX_DIFF_PERCENT)
> + printf("Failed\n");
> + else
> + printf("Passed\n");
> +}
> +
> +static int check_results(struct resctrl_val_param *param)
> +{
> + char *token_array[8], temp[512];

The size of temp[] here does not match ...

> + unsigned long sum_llc_perf_miss = 0;
> + int runs = 0, no_of_bits = 0;
> + FILE *fp;
> +
> + printf("\nChecking for pass/fail\n");
> + fp = fopen(param->filename, "r");
> + if (!fp) {
> + perror("Error in opening file\n");
> +
> + return errno;
> + }
> +
> + while (fgets(temp, 1024, fp)) {

... the user here. sizeof(temp) for the rescue!

Cheers,
Andre.

> + char *token = strtok(temp, ":\t");
> + int fields = 0;
> +
> + while (token) {
> + token_array[fields++] = token;
> + token = strtok(NULL, ":\t");
> + }
> + /*
> + * Discard the first value which is inaccurate due to monitoring
> + * setup transition phase.
> + */
> + if (runs > 0)
> + sum_llc_perf_miss += strtoul(token_array[3], NULL, 0);
> + runs++;
> + }
> +
> + fclose(fp);
> + no_of_bits = count_bits(param->mask);
> +
> + show_cache_info(sum_llc_perf_miss, no_of_bits, param->span);
> +
> + return 0;
> +}
> +
> +void cat_test_cleanup(void)
> +{
> + remove(RESULT_FILE_NAME1);
> + remove(RESULT_FILE_NAME2);
> +}
> +
> +int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
> +{
> + unsigned long l_mask, l_mask_1;
> + int ret, pipefd[2], pipe_message, mum_resctrlfs, sibling_cpu_no;
> + pid_t bm_pid;
> +
> + cache_size = 0;
> + mum_resctrlfs = 1;
> +
> + ret = remount_resctrlfs(mum_resctrlfs);
> + if (ret)
> + return ret;
> +
> + ret = validate_resctrl_feature_request("cat");
> + if (ret)
> + return ret;
> +
> + /* Get default cbm mask for L3/L2 cache */
> + ret = get_cbm_mask(cache_type);
> + if (ret)
> + return ret;
> +
> + long_mask = strtoul(cbm_mask, NULL, 16);
> +
> + /* Get L3/L2 cache size */
> + ret = get_cache_size(cpu_no, cache_type, &cache_size);
> + if (ret)
> + return ret;
> + printf("cache size :%lu\n", cache_size);
> +
> + /* Get max number of bits from default-cabm mask */
> + count_of_bits = count_bits(long_mask);
> +
> + if (n < 1 || n > count_of_bits - 1) {
> + printf("Invalid input value for no_of_bits n!\n");
> + printf("Please Enter value in range 1 to %d\n",
> + count_of_bits - 1);
> + return -1;
> + }
> +
> + /* Get core id from same socket for running another thread */
> + sibling_cpu_no = get_core_sibling(cpu_no);
> + if (sibling_cpu_no < 0)
> + return -1;
> +
> + struct resctrl_val_param param = {
> + .resctrl_val = "cat",
> + .cpu_no = cpu_no,
> + .mum_resctrlfs = 0,
> + .setup = cat_setup,
> + };
> +
> + l_mask = long_mask >> n;
> + l_mask_1 = ~l_mask & long_mask;
> +
> + /* Set param values for parent thread which will be allocated bitmask
> + * with (max_bits - n) bits
> + */
> + param.span = cache_size * (count_of_bits - n) / count_of_bits;
> + strcpy(param.ctrlgrp, "c2");
> + strcpy(param.mongrp, "m2");
> + strcpy(param.filename, RESULT_FILE_NAME2);
> + param.mask = l_mask;
> + param.num_of_runs = 0;
> +
> + if (pipe(pipefd)) {
> + perror("Unable to create pipe");
> + return -1;
> + }
> +
> + bm_pid = fork();
> +
> + /* Set param values for child thread which will be allocated bitmask
> + * with n bits
> + */
> + if (bm_pid == 0) {
> + param.mask = l_mask_1;
> + strcpy(param.ctrlgrp, "c1");
> + strcpy(param.mongrp, "m1");
> + param.span = cache_size * n / count_of_bits;
> + strcpy(param.filename, RESULT_FILE_NAME1);
> + param.num_of_runs = 0;
> + param.cpu_no = sibling_cpu_no;
> + }
> +
> + remove(param.filename);
> +
> + ret = cat_val(&param);
> + if (ret)
> + return ret;
> +
> + ret = check_results(&param);
> + if (ret)
> + return ret;
> +
> + if (bm_pid == 0) {
> + /* Tell parent that child is ready */
> + close(pipefd[0]);
> + pipe_message = 1;
> + write(pipefd[1], &pipe_message, sizeof(pipe_message));
> + close(pipefd[1]);
> + while (1)
> + ;
> + } else {
> + /* Parent waits for child to be ready. */
> + close(pipefd[1]);
> + pipe_message = 0;
> + while (pipe_message != 1)
> + read(pipefd[0], &pipe_message, sizeof(pipe_message));
> + close(pipefd[0]);
> + kill(bm_pid, SIGKILL);
> + }
> +
> + cat_test_cleanup();
> + if (bm_pid)
> + umount_resctrlfs();
> +
> + return 0;
> +}
> diff --git a/tools/testing/selftests/resctrl/fill_buf.c b/tools/testing/selftests/resctrl/fill_buf.c
> index 792a5c40a32a..3244620d3676 100644
> --- a/tools/testing/selftests/resctrl/fill_buf.c
> +++ b/tools/testing/selftests/resctrl/fill_buf.c
> @@ -110,8 +110,11 @@ static int fill_cache_read(unsigned char *start_ptr, unsigned char *end_ptr,
> int ret = 0;
> FILE *fp;
>
> - while (1)
> + while (1) {
> ret = fill_one_span_read(start_ptr, end_ptr);
> + if (!strcmp(resctrl_val, "cat"))
> + break;
> + }
>
> /* Consume read result so that reading memory is not optimized out. */
> fp = fopen("/dev/null", "w");
> @@ -126,8 +129,11 @@ static int fill_cache_read(unsigned char *start_ptr, unsigned char *end_ptr,
> static int fill_cache_write(unsigned char *start_ptr, unsigned char *end_ptr,
> char *resctrl_val)
> {
> - while (1)
> + while (1) {
> fill_one_span_write(start_ptr, end_ptr);
> + if (!strcmp(resctrl_val, "cat"))
> + break;
> + }
>
> return 0;
> }
> diff --git a/tools/testing/selftests/resctrl/resctrl.h b/tools/testing/selftests/resctrl/resctrl.h
> index 2097b02a356d..dadbb3d0cad8 100644
> --- a/tools/testing/selftests/resctrl/resctrl.h
> +++ b/tools/testing/selftests/resctrl/resctrl.h
> @@ -92,6 +92,9 @@ void mba_test_cleanup(void);
> int get_cbm_mask(char *cache_type);
> int get_cache_size(int cpu_no, char *cache_type, unsigned long *cache_size);
> void ctrlc_handler(int signum, siginfo_t *info, void *ptr);
> +int cat_val(struct resctrl_val_param *param);
> +void cat_test_cleanup(void);
> +int cat_perf_miss_val(int cpu_no, int no_of_bits, char *cache_type);
> int cqm_resctrl_val(int cpu_no, int n, char **benchmark_cmd);
> unsigned int count_bits(unsigned long n);
> void cqm_test_cleanup(void);
> diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
> index 5a9af019b5e5..3959b2b0671a 100644
> --- a/tools/testing/selftests/resctrl/resctrl_tests.c
> +++ b/tools/testing/selftests/resctrl/resctrl_tests.c
> @@ -20,7 +20,7 @@ static void cmd_help(void)
> printf("\t-b benchmark_cmd [options]: run specified benchmark for MBM, MBA and CQM");
> printf("\t default benchmark is builtin fill_buf\n");
> printf("\t-t test list: run tests specified in the test list, ");
> - printf("e.g. -t mbm, mba, cqm\n");
> + printf("e.g. -t mbm, mba, cqm, cat\n");
> printf("\t-n no_of_bits: run cache tests using specified no of bits in cache bit mask\n");
> printf("\t-p cpu_no: specify CPU number to run the test. 1 is default\n");
> printf("\t-h: help\n");
> @@ -31,6 +31,7 @@ void tests_cleanup(void)
> mbm_test_cleanup();
> mba_test_cleanup();
> cqm_test_cleanup();
> + cat_test_cleanup();
> }
>
> int main(int argc, char **argv)
> @@ -39,6 +40,7 @@ int main(int argc, char **argv)
> int res, c, cpu_no = 1, span = 250, argc_new = argc, i, no_of_bits = 5;
> int ben_ind, ben_count;
> bool has_ben = false, mbm_test = true, mba_test = true, cqm_test = true;
> + bool cat_test = true;
> char *benchmark_cmd[BENCHMARK_ARGS];
> char bw_report[64], bm_type[64];
>
> @@ -62,6 +64,7 @@ int main(int argc, char **argv)
> mbm_test = false;
> mba_test = false;
> cqm_test = false;
> + cat_test = false;
> while (token) {
> if (!strcmp(token, "mbm")) {
> mbm_test = true;
> @@ -69,6 +72,8 @@ int main(int argc, char **argv)
> mba_test = true;
> } else if (!strcmp(token, "cqm")) {
> cqm_test = true;
> + } else if (!strcmp(token, "cat")) {
> + cat_test = true;
> } else {
> printf("invalid argument\n");
>
> @@ -158,6 +163,13 @@ int main(int argc, char **argv)
> printf("Error in CQM test!\n");
> cqm_test_cleanup();
> }
> + if (cat_test) {
> + printf("\nCAT Test Starting..\n");
> + res = cat_perf_miss_val(cpu_no, no_of_bits, "L3");
> + if (res)
> + printf("Error in CAT test!\n");
> + cat_test_cleanup();
> + }
>
> return 0;
> }
> diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c
> index 6dacd215ace6..137b926955ca 100644
> --- a/tools/testing/selftests/resctrl/resctrlfs.c
> +++ b/tools/testing/selftests/resctrl/resctrlfs.c
> @@ -14,12 +14,14 @@
> #define RESCTRL_MBM "L3 monitoring detected"
> #define RESCTRL_MBA "MB allocation detected"
> #define RESCTRL_CQM "L3 monitoring detected"
> +#define RESCTRL_L3_CAT "L3 allocation detected"
> #define CORE_SIBLINGS_PATH "/sys/bus/cpu/devices/cpu"
>
> enum {
> RESCTRL_FEATURE_MBM,
> RESCTRL_FEATURE_MBA,
> RESCTRL_FEATURE_CQM,
> + RESCTRL_FEATURE_L3_CAT,
> MAX_RESCTRL_FEATURES
> };
>
> @@ -490,6 +492,7 @@ int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, char *resctrl_val)
> FILE *fp;
>
> if ((strcmp(resctrl_val, "mba") == 0) ||
> + (strcmp(resctrl_val, "cat") == 0) ||
> (strcmp(resctrl_val, "cqm") == 0)) {
> if (!schemata) {
> printf("Schemata empty, so not updating\n");
> @@ -507,7 +510,7 @@ int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, char *resctrl_val)
> else
> sprintf(controlgroup, "%s/schemata", RESCTRL_PATH);
>
> - if (!strcmp(resctrl_val, "cqm"))
> + if (!strcmp(resctrl_val, "cat") || !strcmp(resctrl_val, "cqm"))
> sprintf(schema, "%s%d%c%s", "L3:", resource_id, '=',
> schemata);
> if (strcmp(resctrl_val, "mba") == 0)
> @@ -545,7 +548,7 @@ int validate_resctrl_feature_request(char *resctrl_val)
> {
> int resctrl_features_supported[MAX_RESCTRL_FEATURES];
> const char *resctrl_features_list[MAX_RESCTRL_FEATURES] = {
> - "mbm", "mba", "cqm"};
> + "mbm", "mba", "cat", "cqm"};
> int i, valid_resctrl_feature = -1;
> char line[1024];
> FILE *fp;
> @@ -591,7 +594,8 @@ int validate_resctrl_feature_request(char *resctrl_val)
> resctrl_features_supported[RESCTRL_FEATURE_MBA] = 1;
> if ((strstr(line, RESCTRL_CQM)) != NULL)
> resctrl_features_supported[RESCTRL_FEATURE_CQM] = 1;
> -
> + if ((strstr(line, RESCTRL_L3_CAT)) != NULL)
> + resctrl_features_supported[RESCTRL_FEATURE_L3_CAT] = 1;
> }
> fclose(fp);
>