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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /tools/testing/selftests/resctrl/cache.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/resctrl/cache.c')
-rw-r--r-- | tools/testing/selftests/resctrl/cache.c | 308 |
1 files changed, 308 insertions, 0 deletions
diff --git a/tools/testing/selftests/resctrl/cache.c b/tools/testing/selftests/resctrl/cache.c new file mode 100644 index 0000000000..a0318bd3a6 --- /dev/null +++ b/tools/testing/selftests/resctrl/cache.c @@ -0,0 +1,308 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <stdint.h> +#include "resctrl.h" + +struct read_format { + __u64 nr; /* The number of events */ + struct { + __u64 value; /* The value of the event */ + } values[2]; +}; + +static struct perf_event_attr pea_llc_miss; +static struct read_format rf_cqm; +static int fd_lm; +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 void 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; +} + +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 + * @llc_perf_miss: LLC miss counter that is filled on success + * + * 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; + int ret; + + /* Stop counters after one span to get miss rate */ + + ioctl(fd_lm, PERF_EVENT_IOC_DISABLE, 0); + + ret = read(fd_lm, &rf_cqm, sizeof(struct read_format)); + if (ret == -1) { + perror("Could not get llc misses through perf"); + return -1; + } + + total_misses = rf_cqm.values[0].value; + *llc_perf_miss = total_misses; + + return 0; +} + +/* + * Get LLC Occupancy as reported by RESCTRL FS + * For CMT, + * 1. If con_mon grp and mon grp given, then read from mon grp in + * con_mon grp + * 2. If only con_mon grp given, then read from con_mon grp + * 3. If both not given, then read from root con_mon grp + * For CAT, + * 1. If con_mon grp given, then read from it + * 2. If con_mon grp not given, then read from root con_mon grp + * + * Return: =0 on success. <0 on failure. + */ +static int get_llc_occu_resctrl(unsigned long *llc_occupancy) +{ + FILE *fp; + + fp = fopen(llc_occup_path, "r"); + if (!fp) { + perror("Failed to open results file"); + + return errno; + } + if (fscanf(fp, "%lu", llc_occupancy) <= 0) { + perror("Could not get llc occupancy"); + fclose(fp); + + return -1; + } + fclose(fp); + + return 0; +} + +/* + * print_results_cache: the cache results are stored in a file + * @filename: file that stores the results + * @bm_pid: child pid that runs benchmark + * @llc_value: perf miss value / + * llc occupancy value reported by resctrl FS + * + * Return: 0 on success. non-zero on failure. + */ +static int print_results_cache(char *filename, int bm_pid, + unsigned long llc_value) +{ + FILE *fp; + + if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) { + printf("Pid: %d \t LLC_value: %lu\n", bm_pid, + llc_value); + } else { + fp = fopen(filename, "a"); + if (!fp) { + perror("Cannot open results file"); + + return errno; + } + fprintf(fp, "Pid: %d \t llc_value: %lu\n", bm_pid, llc_value); + fclose(fp); + } + + return 0; +} + +int measure_cache_vals(struct resctrl_val_param *param, int bm_pid) +{ + unsigned long llc_perf_miss = 0, llc_occu_resc = 0, llc_value = 0; + int ret; + + /* + * Measure cache miss from perf. + */ + if (!strncmp(param->resctrl_val, CAT_STR, sizeof(CAT_STR))) { + ret = get_llc_perf(&llc_perf_miss); + if (ret < 0) + return ret; + llc_value = llc_perf_miss; + } + + /* + * Measure llc occupancy from resctrl. + */ + if (!strncmp(param->resctrl_val, CMT_STR, sizeof(CMT_STR))) { + ret = get_llc_occu_resctrl(&llc_occu_resc); + if (ret < 0) + return ret; + llc_value = llc_occu_resc; + } + ret = print_results_cache(param->filename, bm_pid, llc_value); + if (ret) + return ret; + + return 0; +} + +/* + * cache_val: execute benchmark and measure LLC occupancy resctrl + * and perf cache miss for the benchmark + * @param: parameters passed to cache_val() + * @span: buffer size for the benchmark + * + * Return: 0 on success. non-zero on failure. + */ +int cat_val(struct resctrl_val_param *param, size_t span) +{ + int 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; + + initialize_llc_perf(); + + /* Test runs until the callback setup() tells the test to stop. */ + while (1) { + ret = param->setup(param); + if (ret == END_OF_TESTS) { + ret = 0; + break; + } + if (ret < 0) + break; + ret = reset_enable_llc_perf(bm_pid, param->cpu_no); + if (ret) + break; + + if (run_fill_buf(span, memflush, operation, true)) { + fprintf(stderr, "Error-running fill buffer\n"); + ret = -1; + goto pe_close; + } + + sleep(1); + ret = measure_cache_vals(param, bm_pid); + if (ret) + goto pe_close; + } + + return ret; + +pe_close: + close(fd_lm); + return ret; +} + +/* + * show_cache_info: show cache test result information + * @sum_llc_val: sum of LLC cache result data + * @no_of_bits: number of bits + * @cache_span: cache span in bytes for CMT or in lines for CAT + * @max_diff: max difference + * @max_diff_percent: max difference percentage + * @num_of_runs: number of runs + * @platform: show test information on this platform + * @cmt: CMT test or CAT test + * + * Return: 0 on success. non-zero on failure. + */ +int show_cache_info(unsigned long sum_llc_val, int no_of_bits, + size_t cache_span, unsigned long max_diff, + unsigned long max_diff_percent, unsigned long num_of_runs, + bool platform, bool cmt) +{ + unsigned long avg_llc_val = 0; + float diff_percent; + long avg_diff = 0; + int ret; + + avg_llc_val = sum_llc_val / num_of_runs; + avg_diff = (long)abs(cache_span - avg_llc_val); + diff_percent = ((float)cache_span - avg_llc_val) / cache_span * 100; + + ret = platform && abs((int)diff_percent) > max_diff_percent && + (cmt ? (abs(avg_diff) > max_diff) : true); + + ksft_print_msg("%s Check cache miss rate within %d%%\n", + ret ? "Fail:" : "Pass:", max_diff_percent); + + ksft_print_msg("Percent diff=%d\n", abs((int)diff_percent)); + ksft_print_msg("Number of bits: %d\n", no_of_bits); + ksft_print_msg("Average LLC val: %lu\n", avg_llc_val); + ksft_print_msg("Cache span (%s): %zu\n", cmt ? "bytes" : "lines", + cache_span); + + return ret; +} |