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// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
*/
#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <unistd.h>
#include <stdbool.h>
#include <string.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "bpf_util.h"
#define SLOTS 100
static void clear_stats(int fd)
{
unsigned int nr_cpus = bpf_num_possible_cpus();
__u64 values[nr_cpus];
__u32 key;
memset(values, 0, sizeof(values));
for (key = 0; key < SLOTS; key++)
bpf_map_update_elem(fd, &key, values, BPF_ANY);
}
const char *color[] = {
"\033[48;5;255m",
"\033[48;5;252m",
"\033[48;5;250m",
"\033[48;5;248m",
"\033[48;5;246m",
"\033[48;5;244m",
"\033[48;5;242m",
"\033[48;5;240m",
"\033[48;5;238m",
"\033[48;5;236m",
"\033[48;5;234m",
"\033[48;5;232m",
};
const int num_colors = ARRAY_SIZE(color);
const char nocolor[] = "\033[00m";
const char *sym[] = {
" ",
" ",
".",
".",
"*",
"*",
"o",
"o",
"O",
"O",
"#",
"#",
};
bool full_range = false;
bool text_only = false;
static void print_banner(void)
{
if (full_range)
printf("|1ns |10ns |100ns |1us |10us |100us"
" |1ms |10ms |100ms |1s |10s\n");
else
printf("|1us |10us |100us |1ms |10ms "
"|100ms |1s |10s\n");
}
static void print_hist(int fd)
{
unsigned int nr_cpus = bpf_num_possible_cpus();
__u64 total_events = 0;
long values[nr_cpus];
__u64 max_cnt = 0;
__u64 cnt[SLOTS];
__u64 value;
__u32 key;
int i;
for (key = 0; key < SLOTS; key++) {
bpf_map_lookup_elem(fd, &key, values);
value = 0;
for (i = 0; i < nr_cpus; i++)
value += values[i];
cnt[key] = value;
total_events += value;
if (value > max_cnt)
max_cnt = value;
}
clear_stats(fd);
for (key = full_range ? 0 : 29; key < SLOTS; key++) {
int c = num_colors * cnt[key] / (max_cnt + 1);
if (text_only)
printf("%s", sym[c]);
else
printf("%s %s", color[c], nocolor);
}
printf(" # %lld\n", total_events);
}
int main(int ac, char **argv)
{
struct bpf_link *links[2];
struct bpf_program *prog;
struct bpf_object *obj;
char filename[256];
int map_fd, i, j = 0;
for (i = 1; i < ac; i++) {
if (strcmp(argv[i], "-a") == 0) {
full_range = true;
} else if (strcmp(argv[i], "-t") == 0) {
text_only = true;
} else if (strcmp(argv[i], "-h") == 0) {
printf("Usage:\n"
" -a display wider latency range\n"
" -t text only\n");
return 1;
}
}
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, "lat_map");
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[j] = bpf_program__attach(prog);
if (libbpf_get_error(links[j])) {
fprintf(stderr, "ERROR: bpf_program__attach failed\n");
links[j] = NULL;
goto cleanup;
}
j++;
}
printf(" heatmap of IO latency\n");
if (text_only)
printf(" %s", sym[num_colors - 1]);
else
printf(" %s %s", color[num_colors - 1], nocolor);
printf(" - many events with this latency\n");
if (text_only)
printf(" %s", sym[0]);
else
printf(" %s %s", color[0], nocolor);
printf(" - few events\n");
for (i = 0; ; i++) {
if (i % 20 == 0)
print_banner();
print_hist(map_fd);
sleep(2);
}
cleanup:
for (j--; j >= 0; j--)
bpf_link__destroy(links[j]);
bpf_object__close(obj);
return 0;
}
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