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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /samples/bpf/lathist_user.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'samples/bpf/lathist_user.c')
-rw-r--r--samples/bpf/lathist_user.c130
1 files changed, 130 insertions, 0 deletions
diff --git a/samples/bpf/lathist_user.c b/samples/bpf/lathist_user.c
new file mode 100644
index 000000000..7d8ff2418
--- /dev/null
+++ b/samples/bpf/lathist_user.c
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2015 BMW Car IT GmbH
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+
+#define MAX_ENTRIES 20
+#define MAX_CPU 4
+#define MAX_STARS 40
+
+struct cpu_hist {
+ long data[MAX_ENTRIES];
+ long max;
+};
+
+static struct cpu_hist cpu_hist[MAX_CPU];
+
+static void stars(char *str, long val, long max, int width)
+{
+ int i;
+
+ for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
+ str[i] = '*';
+ if (val > max)
+ str[i - 1] = '+';
+ str[i] = '\0';
+}
+
+static void print_hist(void)
+{
+ char starstr[MAX_STARS];
+ struct cpu_hist *hist;
+ int i, j;
+
+ /* clear screen */
+ printf("\033[2J");
+
+ for (j = 0; j < MAX_CPU; j++) {
+ hist = &cpu_hist[j];
+
+ /* ignore CPUs without data (maybe offline?) */
+ if (hist->max == 0)
+ continue;
+
+ printf("CPU %d\n", j);
+ printf(" latency : count distribution\n");
+ for (i = 1; i <= MAX_ENTRIES; i++) {
+ stars(starstr, hist->data[i - 1], hist->max, MAX_STARS);
+ printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
+ (1l << i) >> 1, (1l << i) - 1,
+ hist->data[i - 1], MAX_STARS, starstr);
+ }
+ }
+}
+
+static void get_data(int fd)
+{
+ long key, value;
+ int c, i;
+
+ for (i = 0; i < MAX_CPU; i++)
+ cpu_hist[i].max = 0;
+
+ for (c = 0; c < MAX_CPU; c++) {
+ for (i = 0; i < MAX_ENTRIES; i++) {
+ key = c * MAX_ENTRIES + i;
+ bpf_map_lookup_elem(fd, &key, &value);
+
+ cpu_hist[c].data[i] = value;
+ if (value > cpu_hist[c].max)
+ cpu_hist[c].max = value;
+ }
+ }
+}
+
+int main(int argc, char **argv)
+{
+ struct bpf_link *links[2];
+ struct bpf_program *prog;
+ struct bpf_object *obj;
+ char filename[256];
+ int map_fd, i = 0;
+
+ 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;
+ }
+
+ /* load BPF program */
+ if (bpf_object__load(obj)) {
+ fprintf(stderr, "ERROR: loading BPF object file failed\n");
+ goto cleanup;
+ }
+
+ map_fd = bpf_object__find_map_fd_by_name(obj, "my_lat");
+ if (map_fd < 0) {
+ fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+ goto cleanup;
+ }
+
+ bpf_object__for_each_program(prog, obj) {
+ links[i] = bpf_program__attach(prog);
+ if (libbpf_get_error(links[i])) {
+ fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+ links[i] = NULL;
+ goto cleanup;
+ }
+ i++;
+ }
+
+ while (1) {
+ get_data(map_fd);
+ print_hist();
+ sleep(5);
+ }
+
+cleanup:
+ for (i--; i >= 0; i--)
+ bpf_link__destroy(links[i]);
+
+ bpf_object__close(obj);
+ return 0;
+}