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// 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->read_format = PERF_FORMAT_GROUP;
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;
}
void perf_event_initialize_read_format(struct perf_event_read *pe_read)
{
memset(pe_read, 0, sizeof(*pe_read));
pe_read->nr = 1;
}
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("Error opening leader");
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, int bm_pid, __u64 llc_value)
{
FILE *fp;
if (strcmp(filename, "stdio") == 0 || strcmp(filename, "stderr") == 0) {
printf("Pid: %d \t LLC_value: %llu\n", 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", 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, struct perf_event_read *pe_read,
const char *filename, int bm_pid)
{
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, pe_read, sizeof(*pe_read));
if (ret == -1) {
ksft_perror("Could not get perf value");
return -1;
}
return print_results_cache(filename, bm_pid, pe_read->values[0].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, int 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);
}
/*
* 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);
}
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