Something went wrong. Try again.
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Something went wrong. Try again.
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196// SPDX-License-Identifier: GPL-2.0
#include <stdint.h>#include "resctrl.h"
char llc_occup_path[1024];
void perf_event_attr_initialize(struct perf_event_attr *pea, __u64 config){ memset(pea, 0, sizeof(*pea)); pea->type = PERF_TYPE_HARDWARE; pea->size = sizeof(*pea); pea->exclude_kernel = 1; pea->exclude_hv = 1; pea->exclude_idle = 1; pea->exclude_callchain_kernel = 1; pea->inherit = 1; pea->exclude_guest = 1; pea->disabled = 1; pea->config = config;}
/* Start counters to log values */int perf_event_reset_enable(int pe_fd){ int ret;
ret = ioctl(pe_fd, PERF_EVENT_IOC_RESET, 0); if (ret < 0) return ret;
ret = ioctl(pe_fd, PERF_EVENT_IOC_ENABLE, 0); if (ret < 0) return ret;
return 0;}
int perf_open(struct perf_event_attr *pea, pid_t pid, int cpu_no){ int pe_fd;
pe_fd = perf_event_open(pea, pid, cpu_no, -1, PERF_FLAG_FD_CLOEXEC); if (pe_fd == -1) { ksft_perror("Unable to set up performance monitoring"); return -1; }
perf_event_reset_enable(pe_fd);
return pe_fd;}
/* * 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) { ksft_perror("Failed to open results file");
return -1; } if (fscanf(fp, "%lu", llc_occupancy) <= 0) { ksft_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, < 0 on error. */static int print_results_cache(const char *filename, pid_t bm_pid, __u64 llc_value){ FILE *fp;
if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) { printf("Pid: %d \t LLC_value: %llu\n", (int)bm_pid, llc_value); } else { fp = fopen(filename, "a"); if (!fp) { ksft_perror("Cannot open results file");
return -1; } fprintf(fp, "Pid: %d \t llc_value: %llu\n", (int)bm_pid, llc_value); fclose(fp); }
return 0;}
/* * perf_event_measure - Measure perf events * @filename: Filename for writing the results * @bm_pid: PID that runs the benchmark * * Measures perf events (e.g., cache misses) and writes the results into * @filename. @bm_pid is written to the results file along with the measured * value. * * Return: =0 on success. <0 on failure. */int perf_event_measure(int pe_fd, const char *filename, pid_t bm_pid){ __u64 value; int ret;
/* Stop counters after one span to get miss rate */ ret = ioctl(pe_fd, PERF_EVENT_IOC_DISABLE, 0); if (ret < 0) return ret;
ret = read(pe_fd, &value, sizeof(value)); if (ret == -1) { ksft_perror("Could not get perf value"); return -1; }
return print_results_cache(filename, bm_pid, value);}
/* * measure_llc_resctrl - Measure resctrl LLC value from resctrl * @filename: Filename for writing the results * @bm_pid: PID that runs the benchmark * * Measures LLC occupancy from resctrl and writes the results into @filename. * @bm_pid is written to the results file along with the measured value. * * Return: =0 on success. <0 on failure. */int measure_llc_resctrl(const char *filename, pid_t bm_pid){ unsigned long llc_occu_resc = 0; int ret;
ret = get_llc_occu_resctrl(&llc_occu_resc); if (ret < 0) return ret;
return print_results_cache(filename, bm_pid, llc_occu_resc);}
/* * Reduce L2 allocation to minimum when testing L3 cache allocation. */int minimize_l2_occupancy(const struct resctrl_test *test, const struct user_params *uparams, const struct resctrl_val_param *param){ if (!strcmp(test->resource, "L3") && resctrl_resource_exists("L2")) return write_schemata(param->ctrlgrp, "0x1", uparams->cpu, "L2");
return 0;}
/* * show_cache_info - Show generic cache test information * @no_of_bits: Number of bits * @avg_llc_val: Average of LLC cache result data * @cache_span: Cache span * @lines: @cache_span in lines or bytes */void show_cache_info(int no_of_bits, __u64 avg_llc_val, size_t cache_span, bool lines){ ksft_print_msg("Number of bits: %d\n", no_of_bits); ksft_print_msg("Average LLC val: %llu\n", avg_llc_val); ksft_print_msg("Cache span (%s): %zu\n", lines ? "lines" : "bytes", cache_span);}