// 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 <sys/resource.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 rlimit r = {1024*1024, RLIM_INFINITY}; 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; } } if (setrlimit(RLIMIT_MEMLOCK, &r)) { perror("setrlimit(RLIMIT_MEMLOCK)"); 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; }