1 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
2
3 /*
4 * slabratetop Trace slab kmem_cache_alloc by process.
5 * Copyright (c) 2022 Rong Tao
6 *
7 * Based on slabratetop(8) from BCC by Brendan Gregg.
8 * 07-Jan-2022 Rong Tao Created this.
9 */
10 #include <argp.h>
11 #include <errno.h>
12 #include <signal.h>
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <string.h>
16 #include <time.h>
17 #include <unistd.h>
18
19 #include <bpf/libbpf.h>
20 #include <bpf/bpf.h>
21 #include "slabratetop.h"
22 #include "slabratetop.skel.h"
23 #include "trace_helpers.h"
24
25 #define warn(...) fprintf(stderr, __VA_ARGS__)
26 #define OUTPUT_ROWS_LIMIT 10240
27
28 enum SORT_BY {
29 SORT_BY_CACHE_NAME,
30 SORT_BY_CACHE_COUNT,
31 SORT_BY_CACHE_SIZE,
32 };
33
34 static volatile sig_atomic_t exiting = 0;
35
36 static pid_t target_pid = 0;
37 static bool clear_screen = true;
38 static int output_rows = 20;
39 static int sort_by = SORT_BY_CACHE_SIZE;
40 static int interval = 1;
41 static int count = 99999999;
42 static bool verbose = false;
43
44 const char *argp_program_version = "slabratetop 0.1";
45 const char *argp_program_bug_address =
46 "https://github.com/iovisor/bcc/tree/master/libbpf-tools";
47 const char argp_program_doc[] =
48 "Trace slab kmem cache alloc by process.\n"
49 "\n"
50 "USAGE: slabratetop [-h] [-p PID] [interval] [count]\n"
51 "\n"
52 "EXAMPLES:\n"
53 " slabratetop # slab rate top, refresh every 1s\n"
54 " slabratetop -p 181 # only trace PID 181\n"
55 " slabratetop -s count # sort columns by count\n"
56 " slabratetop -r 100 # print 100 rows\n"
57 " slabratetop 5 10 # 5s summaries, 10 times\n";
58
59 static const struct argp_option opts[] = {
60 { "pid", 'p', "PID", 0, "Process ID to trace" },
61 { "noclear", 'C', NULL, 0, "Don't clear the screen" },
62 { "sort", 's', "SORT", 0, "Sort columns, default size [name, count, size]" },
63 { "rows", 'r', "ROWS", 0, "Maximum rows to print, default 20" },
64 { "verbose", 'v', NULL, 0, "Verbose debug output" },
65 { NULL, 'h', NULL, OPTION_HIDDEN, "Show the full help" },
66 {},
67 };
68
parse_arg(int key,char * arg,struct argp_state * state)69 static error_t parse_arg(int key, char *arg, struct argp_state *state)
70 {
71 long pid, rows;
72 static int pos_args;
73
74 switch (key) {
75 case 'p':
76 errno = 0;
77 pid = strtol(arg, NULL, 10);
78 if (errno || pid <= 0) {
79 warn("invalid PID: %s\n", arg);
80 argp_usage(state);
81 }
82 target_pid = pid;
83 break;
84 case 'C':
85 clear_screen = false;
86 break;
87 case 's':
88 if (!strcmp(arg, "name")) {
89 sort_by = SORT_BY_CACHE_NAME;
90 } else if (!strcmp(arg, "count")) {
91 sort_by = SORT_BY_CACHE_COUNT;
92 } else if (!strcmp(arg, "size")) {
93 sort_by = SORT_BY_CACHE_SIZE;
94 } else {
95 warn("invalid sort method: %s\n", arg);
96 argp_usage(state);
97 }
98 break;
99 case 'r':
100 errno = 0;
101 rows = strtol(arg, NULL, 10);
102 if (errno || rows <= 0) {
103 warn("invalid rows: %s\n", arg);
104 argp_usage(state);
105 }
106 output_rows = rows;
107 if (output_rows > OUTPUT_ROWS_LIMIT)
108 output_rows = OUTPUT_ROWS_LIMIT;
109 break;
110 case 'v':
111 verbose = true;
112 break;
113 case 'h':
114 argp_state_help(state, stderr, ARGP_HELP_STD_HELP);
115 break;
116 case ARGP_KEY_ARG:
117 errno = 0;
118 if (pos_args == 0) {
119 interval = strtol(arg, NULL, 10);
120 if (errno || interval <= 0) {
121 warn("invalid interval\n");
122 argp_usage(state);
123 }
124 } else if (pos_args == 1) {
125 count = strtol(arg, NULL, 10);
126 if (errno || count <= 0) {
127 warn("invalid count\n");
128 argp_usage(state);
129 }
130 } else {
131 warn("unrecognized positional argument: %s\n", arg);
132 argp_usage(state);
133 }
134 pos_args++;
135 break;
136 default:
137 return ARGP_ERR_UNKNOWN;
138 }
139 return 0;
140 }
141
libbpf_print_fn(enum libbpf_print_level level,const char * format,va_list args)142 static int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)
143 {
144 if (level == LIBBPF_DEBUG && !verbose)
145 return 0;
146 return vfprintf(stderr, format, args);
147 }
148
sig_int(int signo)149 static void sig_int(int signo)
150 {
151 exiting = 1;
152 }
153
sort_column(const void * obj1,const void * obj2)154 static int sort_column(const void *obj1, const void *obj2)
155 {
156 struct slabrate_info *s1 = (struct slabrate_info *)obj1;
157 struct slabrate_info *s2 = (struct slabrate_info *)obj2;
158
159 if (sort_by == SORT_BY_CACHE_NAME) {
160 return strcasecmp(s1->name, s2->name);
161 } else if (sort_by == SORT_BY_CACHE_COUNT) {
162 return s2->count - s1->count;
163 } else if (sort_by == SORT_BY_CACHE_SIZE) {
164 return s2->size - s1->size;
165 } else {
166 return s2->size - s1->size;
167 }
168 }
169
print_stat(struct slabratetop_bpf * obj)170 static int print_stat(struct slabratetop_bpf *obj)
171 {
172 FILE *f;
173 time_t t;
174 struct tm *tm;
175 char ts[16], buf[256];
176 char *key, **prev_key = NULL;
177 static struct slabrate_info values[OUTPUT_ROWS_LIMIT];
178 int n, i, err = 0, rows = 0;
179 int fd = bpf_map__fd(obj->maps.slab_entries);
180
181 f = fopen("/proc/loadavg", "r");
182 if (f) {
183 time(&t);
184 tm = localtime(&t);
185 strftime(ts, sizeof(ts), "%H:%M:%S", tm);
186 memset(buf, 0 , sizeof(buf));
187 n = fread(buf, 1, sizeof(buf), f);
188 if (n)
189 printf("%8s loadavg: %s\n", ts, buf);
190 fclose(f);
191 }
192
193 printf("%-32s %6s %10s\n", "CACHE", "ALLOCS", "BYTES");
194
195 while (1) {
196 err = bpf_map_get_next_key(fd, prev_key, &key);
197 if (err) {
198 if (errno == ENOENT) {
199 err = 0;
200 break;
201 }
202 warn("bpf_map_get_next_key failed: %s\n", strerror(errno));
203 return err;
204 }
205 err = bpf_map_lookup_elem(fd, &key, &values[rows++]);
206 if (err) {
207 warn("bpf_map_lookup_elem failed: %s\n", strerror(errno));
208 return err;
209 }
210 prev_key = &key;
211 }
212
213 qsort(values, rows, sizeof(struct slabrate_info), sort_column);
214 rows = rows < output_rows ? rows : output_rows;
215 for (i = 0; i < rows; i++)
216 printf("%-32s %6lld %10lld\n",
217 values[i].name, values[i].count, values[i].size);
218
219 printf("\n");
220 prev_key = NULL;
221
222 while (1) {
223 err = bpf_map_get_next_key(fd, prev_key, &key);
224 if (err) {
225 if (errno == ENOENT) {
226 err = 0;
227 break;
228 }
229 warn("bpf_map_get_next_key failed: %s\n", strerror(errno));
230 return err;
231 }
232 err = bpf_map_delete_elem(fd, &key);
233 if (err) {
234 warn("bpf_map_delete_elem failed: %s\n", strerror(errno));
235 return err;
236 }
237 prev_key = &key;
238 }
239 return err;
240 }
241
main(int argc,char ** argv)242 int main(int argc, char **argv)
243 {
244 static const struct argp argp = {
245 .options = opts,
246 .parser = parse_arg,
247 .doc = argp_program_doc,
248 };
249 struct slabratetop_bpf *obj;
250 int err;
251
252 err = argp_parse(&argp, argc, argv, 0, NULL, NULL);
253 if (err)
254 return err;
255
256 libbpf_set_print(libbpf_print_fn);
257
258 obj = slabratetop_bpf__open();
259 if (!obj) {
260 warn("failed to open BPF object\n");
261 return 1;
262 }
263
264 obj->rodata->target_pid = target_pid;
265
266 err = slabratetop_bpf__load(obj);
267 if (err) {
268 warn("failed to load BPF object: %d\n", err);
269 goto cleanup;
270 }
271
272 err = slabratetop_bpf__attach(obj);
273 if (err) {
274 warn("failed to attach BPF programs: %d\n", err);
275 goto cleanup;
276 }
277
278 if (signal(SIGINT, sig_int) == SIG_ERR) {
279 warn("can't set signal handler: %s\n", strerror(errno));
280 err = 1;
281 goto cleanup;
282 }
283
284 while (1) {
285 sleep(interval);
286
287 if (clear_screen) {
288 err = system("clear");
289 if (err)
290 goto cleanup;
291 }
292
293 err = print_stat(obj);
294 if (err)
295 goto cleanup;
296
297 count--;
298 if (exiting || !count)
299 goto cleanup;
300 }
301
302 cleanup:
303 slabratetop_bpf__destroy(obj);
304
305 return err != 0;
306 }
307