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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /samples/bpf/cpustat_user.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'samples/bpf/cpustat_user.c')
-rw-r--r-- | samples/bpf/cpustat_user.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/samples/bpf/cpustat_user.c b/samples/bpf/cpustat_user.c new file mode 100644 index 000000000..ab90bb08a --- /dev/null +++ b/samples/bpf/cpustat_user.c @@ -0,0 +1,251 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <signal.h> +#include <sched.h> +#include <string.h> +#include <unistd.h> +#include <fcntl.h> +#include <locale.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <sys/wait.h> + +#include <bpf/bpf.h> +#include <bpf/libbpf.h> + +static int cstate_map_fd, pstate_map_fd; + +#define MAX_CPU 8 +#define MAX_PSTATE_ENTRIES 5 +#define MAX_CSTATE_ENTRIES 3 +#define MAX_STARS 40 + +#define CPUFREQ_MAX_SYSFS_PATH "/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq" +#define CPUFREQ_LOWEST_FREQ "208000" +#define CPUFREQ_HIGHEST_FREQ "12000000" + +struct cpu_stat_data { + unsigned long cstate[MAX_CSTATE_ENTRIES]; + unsigned long pstate[MAX_PSTATE_ENTRIES]; +}; + +static struct cpu_stat_data stat_data[MAX_CPU]; + +static void cpu_stat_print(void) +{ + int i, j; + char state_str[sizeof("cstate-9")]; + struct cpu_stat_data *data; + + /* Clear screen */ + printf("\033[2J"); + + /* Header */ + printf("\nCPU states statistics:\n"); + printf("%-10s ", "state(ms)"); + + for (i = 0; i < MAX_CSTATE_ENTRIES; i++) { + sprintf(state_str, "cstate-%d", i); + printf("%-11s ", state_str); + } + + for (i = 0; i < MAX_PSTATE_ENTRIES; i++) { + sprintf(state_str, "pstate-%d", i); + printf("%-11s ", state_str); + } + + printf("\n"); + + for (j = 0; j < MAX_CPU; j++) { + data = &stat_data[j]; + + printf("CPU-%-6d ", j); + for (i = 0; i < MAX_CSTATE_ENTRIES; i++) + printf("%-11ld ", data->cstate[i] / 1000000); + + for (i = 0; i < MAX_PSTATE_ENTRIES; i++) + printf("%-11ld ", data->pstate[i] / 1000000); + + printf("\n"); + } +} + +static void cpu_stat_update(int cstate_fd, int pstate_fd) +{ + unsigned long key, value; + int c, i; + + for (c = 0; c < MAX_CPU; c++) { + for (i = 0; i < MAX_CSTATE_ENTRIES; i++) { + key = c * MAX_CSTATE_ENTRIES + i; + bpf_map_lookup_elem(cstate_fd, &key, &value); + stat_data[c].cstate[i] = value; + } + + for (i = 0; i < MAX_PSTATE_ENTRIES; i++) { + key = c * MAX_PSTATE_ENTRIES + i; + bpf_map_lookup_elem(pstate_fd, &key, &value); + stat_data[c].pstate[i] = value; + } + } +} + +/* + * This function is copied from 'idlestat' tool function + * idlestat_wake_all() in idlestate.c. + * + * It sets the self running task affinity to cpus one by one so can wake up + * the specific CPU to handle scheduling; this results in all cpus can be + * waken up once and produce ftrace event 'trace_cpu_idle'. + */ +static int cpu_stat_inject_cpu_idle_event(void) +{ + int rcpu, i, ret; + cpu_set_t cpumask; + cpu_set_t original_cpumask; + + ret = sysconf(_SC_NPROCESSORS_CONF); + if (ret < 0) + return -1; + + rcpu = sched_getcpu(); + if (rcpu < 0) + return -1; + + /* Keep track of the CPUs we will run on */ + sched_getaffinity(0, sizeof(original_cpumask), &original_cpumask); + + for (i = 0; i < ret; i++) { + + /* Pointless to wake up ourself */ + if (i == rcpu) + continue; + + /* Pointless to wake CPUs we will not run on */ + if (!CPU_ISSET(i, &original_cpumask)) + continue; + + CPU_ZERO(&cpumask); + CPU_SET(i, &cpumask); + + sched_setaffinity(0, sizeof(cpumask), &cpumask); + } + + /* Enable all the CPUs of the original mask */ + sched_setaffinity(0, sizeof(original_cpumask), &original_cpumask); + return 0; +} + +/* + * It's possible to have no any frequency change for long time and cannot + * get ftrace event 'trace_cpu_frequency' for long period, this introduces + * big deviation for pstate statistics. + * + * To solve this issue, below code forces to set 'scaling_max_freq' to 208MHz + * for triggering ftrace event 'trace_cpu_frequency' and then recovery back to + * the maximum frequency value 1.2GHz. + */ +static int cpu_stat_inject_cpu_frequency_event(void) +{ + int len, fd; + + fd = open(CPUFREQ_MAX_SYSFS_PATH, O_WRONLY); + if (fd < 0) { + printf("failed to open scaling_max_freq, errno=%d\n", errno); + return fd; + } + + len = write(fd, CPUFREQ_LOWEST_FREQ, strlen(CPUFREQ_LOWEST_FREQ)); + if (len < 0) { + printf("failed to open scaling_max_freq, errno=%d\n", errno); + goto err; + } + + len = write(fd, CPUFREQ_HIGHEST_FREQ, strlen(CPUFREQ_HIGHEST_FREQ)); + if (len < 0) { + printf("failed to open scaling_max_freq, errno=%d\n", errno); + goto err; + } + +err: + close(fd); + return len; +} + +static void int_exit(int sig) +{ + cpu_stat_inject_cpu_idle_event(); + cpu_stat_inject_cpu_frequency_event(); + cpu_stat_update(cstate_map_fd, pstate_map_fd); + cpu_stat_print(); + exit(0); +} + +int main(int argc, char **argv) +{ + struct bpf_link *link = NULL; + struct bpf_program *prog; + struct bpf_object *obj; + char filename[256]; + int ret; + + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + return 0; + } + + prog = bpf_object__find_program_by_name(obj, "bpf_prog1"); + if (!prog) { + printf("finding a prog in obj file failed\n"); + goto cleanup; + } + + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } + + cstate_map_fd = bpf_object__find_map_fd_by_name(obj, "cstate_duration"); + pstate_map_fd = bpf_object__find_map_fd_by_name(obj, "pstate_duration"); + if (cstate_map_fd < 0 || pstate_map_fd < 0) { + fprintf(stderr, "ERROR: finding a map in obj file failed\n"); + goto cleanup; + } + + link = bpf_program__attach(prog); + if (libbpf_get_error(link)) { + fprintf(stderr, "ERROR: bpf_program__attach failed\n"); + link = NULL; + goto cleanup; + } + + ret = cpu_stat_inject_cpu_idle_event(); + if (ret < 0) + return 1; + + ret = cpu_stat_inject_cpu_frequency_event(); + if (ret < 0) + return 1; + + signal(SIGINT, int_exit); + signal(SIGTERM, int_exit); + + while (1) { + cpu_stat_update(cstate_map_fd, pstate_map_fd); + cpu_stat_print(); + sleep(5); + } + +cleanup: + bpf_link__destroy(link); + bpf_object__close(obj); + return 0; +} |