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// 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()
*
* Return: 0 on success. non-zero on failure.
*/
int cat_val(struct resctrl_val_param *param)
{
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;
if (!strncmp(resctrl_val, CAT_STR, sizeof(CAT_STR)))
initialize_llc_perf();
/* Test runs until the callback setup() tells the test to stop. */
while (1) {
if (!strncmp(resctrl_val, CAT_STR, sizeof(CAT_STR))) {
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(param->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;
close(fd_lm);
} else {
break;
}
}
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;
}
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