// 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.bpf.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;}