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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /samples/bpf/cpustat_user.c
parentInitial commit. (diff)
downloadlinux-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 'samples/bpf/cpustat_user.c')
-rw-r--r--samples/bpf/cpustat_user.c251
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 0000000000..ab90bb08a2
--- /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;
+}