1// SPDX-License-Identifier: GPL-2.0
2/* getdelays.c
3 *
4 * Utility to get per-pid and per-tgid delay accounting statistics
5 * Also illustrates usage of the taskstats interface
6 *
7 * Copyright (C) Shailabh Nagar, IBM Corp. 2005
8 * Copyright (C) Balbir Singh, IBM Corp. 2006
9 * Copyright (c) Jay Lan, SGI. 2006
10 *
11 * Compile with
12 *	gcc -I/usr/src/linux/include getdelays.c -o getdelays
13 */
14
15#include <stdio.h>
16#include <stdlib.h>
17#include <errno.h>
18#include <unistd.h>
19#include <poll.h>
20#include <string.h>
21#include <fcntl.h>
22#include <sys/types.h>
23#include <sys/stat.h>
24#include <sys/socket.h>
25#include <sys/wait.h>
26#include <signal.h>
27
28#include <linux/genetlink.h>
29#include <linux/taskstats.h>
30#include <linux/cgroupstats.h>
31
32/*
33 * Generic macros for dealing with netlink sockets. Might be duplicated
34 * elsewhere. It is recommended that commercial grade applications use
35 * libnl or libnetlink and use the interfaces provided by the library
36 */
37#define GENLMSG_DATA(glh)	((void *)(NLMSG_DATA(glh) + GENL_HDRLEN))
38#define GENLMSG_PAYLOAD(glh)	(NLMSG_PAYLOAD(glh, 0) - GENL_HDRLEN)
39#define NLA_DATA(na)		((void *)((char*)(na) + NLA_HDRLEN))
40#define NLA_PAYLOAD(len)	(len - NLA_HDRLEN)
41
42#define err(code, fmt, arg...)			\
43	do {					\
44		fprintf(stderr, fmt, ##arg);	\
45		exit(code);			\
46	} while (0)
47
48int done;
49int rcvbufsz;
50char name[100];
51int dbg;
52int print_delays;
53int print_io_accounting;
54int print_task_context_switch_counts;
55
56#define PRINTF(fmt, arg...) {			\
57	    if (dbg) {				\
58		printf(fmt, ##arg);		\
59	    }					\
60	}
61
62/* Maximum size of response requested or message sent */
63#define MAX_MSG_SIZE	1024
64/* Maximum number of cpus expected to be specified in a cpumask */
65#define MAX_CPUS	32
66
67struct msgtemplate {
68	struct nlmsghdr n;
69	struct genlmsghdr g;
70	char buf[MAX_MSG_SIZE];
71};
72
73char cpumask[100+6*MAX_CPUS];
74
75static void usage(void)
76{
77	fprintf(stderr, "getdelays [-dilv] [-w logfile] [-r bufsize] "
78			"[-m cpumask] [-t tgid] [-p pid]\n");
79	fprintf(stderr, "  -d: print delayacct stats\n");
80	fprintf(stderr, "  -i: print IO accounting (works only with -p)\n");
81	fprintf(stderr, "  -l: listen forever\n");
82	fprintf(stderr, "  -v: debug on\n");
83	fprintf(stderr, "  -C: container path\n");
84}
85
86/*
87 * Create a raw netlink socket and bind
88 */
89static int create_nl_socket(int protocol)
90{
91	int fd;
92	struct sockaddr_nl local;
93
94	fd = socket(AF_NETLINK, SOCK_RAW, protocol);
95	if (fd < 0)
96		return -1;
97
98	if (rcvbufsz)
99		if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF,
100				&rcvbufsz, sizeof(rcvbufsz)) < 0) {
101			fprintf(stderr, "Unable to set socket rcv buf size to %d\n",
102				rcvbufsz);
103			goto error;
104		}
105
106	memset(&local, 0, sizeof(local));
107	local.nl_family = AF_NETLINK;
108
109	if (bind(fd, (struct sockaddr *) &local, sizeof(local)) < 0)
110		goto error;
111
112	return fd;
113error:
114	close(fd);
115	return -1;
116}
117
118
119static int send_cmd(int sd, __u16 nlmsg_type, __u32 nlmsg_pid,
120	     __u8 genl_cmd, __u16 nla_type,
121	     void *nla_data, int nla_len)
122{
123	struct nlattr *na;
124	struct sockaddr_nl nladdr;
125	int r, buflen;
126	char *buf;
127
128	struct msgtemplate msg;
129
130	msg.n.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
131	msg.n.nlmsg_type = nlmsg_type;
132	msg.n.nlmsg_flags = NLM_F_REQUEST;
133	msg.n.nlmsg_seq = 0;
134	msg.n.nlmsg_pid = nlmsg_pid;
135	msg.g.cmd = genl_cmd;
136	msg.g.version = 0x1;
137	na = (struct nlattr *) GENLMSG_DATA(&msg);
138	na->nla_type = nla_type;
139	na->nla_len = nla_len + NLA_HDRLEN;
140	memcpy(NLA_DATA(na), nla_data, nla_len);
141	msg.n.nlmsg_len += NLMSG_ALIGN(na->nla_len);
142
143	buf = (char *) &msg;
144	buflen = msg.n.nlmsg_len ;
145	memset(&nladdr, 0, sizeof(nladdr));
146	nladdr.nl_family = AF_NETLINK;
147	while ((r = sendto(sd, buf, buflen, 0, (struct sockaddr *) &nladdr,
148			   sizeof(nladdr))) < buflen) {
149		if (r > 0) {
150			buf += r;
151			buflen -= r;
152		} else if (errno != EAGAIN)
153			return -1;
154	}
155	return 0;
156}
157
158
159/*
160 * Probe the controller in genetlink to find the family id
161 * for the TASKSTATS family
162 */
163static int get_family_id(int sd)
164{
165	struct {
166		struct nlmsghdr n;
167		struct genlmsghdr g;
168		char buf[256];
169	} ans;
170
171	int id = 0, rc;
172	struct nlattr *na;
173	int rep_len;
174
175	strcpy(name, TASKSTATS_GENL_NAME);
176	rc = send_cmd(sd, GENL_ID_CTRL, getpid(), CTRL_CMD_GETFAMILY,
177			CTRL_ATTR_FAMILY_NAME, (void *)name,
178			strlen(TASKSTATS_GENL_NAME)+1);
179	if (rc < 0)
180		return 0;	/* sendto() failure? */
181
182	rep_len = recv(sd, &ans, sizeof(ans), 0);
183	if (ans.n.nlmsg_type == NLMSG_ERROR ||
184	    (rep_len < 0) || !NLMSG_OK((&ans.n), rep_len))
185		return 0;
186
187	na = (struct nlattr *) GENLMSG_DATA(&ans);
188	na = (struct nlattr *) ((char *) na + NLA_ALIGN(na->nla_len));
189	if (na->nla_type == CTRL_ATTR_FAMILY_ID) {
190		id = *(__u16 *) NLA_DATA(na);
191	}
192	return id;
193}
194
195#define average_ms(t, c) (t / 1000000ULL / (c ? c : 1))
196
197static void print_delayacct(struct taskstats *t)
198{
199	printf("\n\nCPU   %15s%15s%15s%15s%15s\n"
200	       "      %15llu%15llu%15llu%15llu%15.3fms\n"
201	       "IO    %15s%15s%15s\n"
202	       "      %15llu%15llu%15llums\n"
203	       "SWAP  %15s%15s%15s\n"
204	       "      %15llu%15llu%15llums\n"
205	       "RECLAIM  %12s%15s%15s\n"
206	       "      %15llu%15llu%15llums\n"
207	       "THRASHING%12s%15s%15s\n"
208	       "      %15llu%15llu%15llums\n",
209	       "count", "real total", "virtual total",
210	       "delay total", "delay average",
211	       (unsigned long long)t->cpu_count,
212	       (unsigned long long)t->cpu_run_real_total,
213	       (unsigned long long)t->cpu_run_virtual_total,
214	       (unsigned long long)t->cpu_delay_total,
215	       average_ms((double)t->cpu_delay_total, t->cpu_count),
216	       "count", "delay total", "delay average",
217	       (unsigned long long)t->blkio_count,
218	       (unsigned long long)t->blkio_delay_total,
219	       average_ms(t->blkio_delay_total, t->blkio_count),
220	       "count", "delay total", "delay average",
221	       (unsigned long long)t->swapin_count,
222	       (unsigned long long)t->swapin_delay_total,
223	       average_ms(t->swapin_delay_total, t->swapin_count),
224	       "count", "delay total", "delay average",
225	       (unsigned long long)t->freepages_count,
226	       (unsigned long long)t->freepages_delay_total,
227	       average_ms(t->freepages_delay_total, t->freepages_count),
228	       "count", "delay total", "delay average",
229	       (unsigned long long)t->thrashing_count,
230	       (unsigned long long)t->thrashing_delay_total,
231	       average_ms(t->thrashing_delay_total, t->thrashing_count));
232}
233
234static void task_context_switch_counts(struct taskstats *t)
235{
236	printf("\n\nTask   %15s%15s\n"
237	       "       %15llu%15llu\n",
238	       "voluntary", "nonvoluntary",
239	       (unsigned long long)t->nvcsw, (unsigned long long)t->nivcsw);
240}
241
242static void print_cgroupstats(struct cgroupstats *c)
243{
244	printf("sleeping %llu, blocked %llu, running %llu, stopped %llu, "
245		"uninterruptible %llu\n", (unsigned long long)c->nr_sleeping,
246		(unsigned long long)c->nr_io_wait,
247		(unsigned long long)c->nr_running,
248		(unsigned long long)c->nr_stopped,
249		(unsigned long long)c->nr_uninterruptible);
250}
251
252
253static void print_ioacct(struct taskstats *t)
254{
255	printf("%s: read=%llu, write=%llu, cancelled_write=%llu\n",
256		t->ac_comm,
257		(unsigned long long)t->read_bytes,
258		(unsigned long long)t->write_bytes,
259		(unsigned long long)t->cancelled_write_bytes);
260}
261
262int main(int argc, char *argv[])
263{
264	int c, rc, rep_len, aggr_len, len2;
265	int cmd_type = TASKSTATS_CMD_ATTR_UNSPEC;
266	__u16 id;
267	__u32 mypid;
268
269	struct nlattr *na;
270	int nl_sd = -1;
271	int len = 0;
272	pid_t tid = 0;
273	pid_t rtid = 0;
274
275	int fd = 0;
276	int count = 0;
277	int write_file = 0;
278	int maskset = 0;
279	char *logfile = NULL;
280	int loop = 0;
281	int containerset = 0;
282	char *containerpath = NULL;
283	int cfd = 0;
284	int forking = 0;
285	sigset_t sigset;
286
287	struct msgtemplate msg;
288
289	while (!forking) {
290		c = getopt(argc, argv, "qdiw:r:m:t:p:vlC:c:");
291		if (c < 0)
292			break;
293
294		switch (c) {
295		case 'd':
296			printf("print delayacct stats ON\n");
297			print_delays = 1;
298			break;
299		case 'i':
300			printf("printing IO accounting\n");
301			print_io_accounting = 1;
302			break;
303		case 'q':
304			printf("printing task/process context switch rates\n");
305			print_task_context_switch_counts = 1;
306			break;
307		case 'C':
308			containerset = 1;
309			containerpath = optarg;
310			break;
311		case 'w':
312			logfile = strdup(optarg);
313			printf("write to file %s\n", logfile);
314			write_file = 1;
315			break;
316		case 'r':
317			rcvbufsz = atoi(optarg);
318			printf("receive buf size %d\n", rcvbufsz);
319			if (rcvbufsz < 0)
320				err(1, "Invalid rcv buf size\n");
321			break;
322		case 'm':
323			strncpy(cpumask, optarg, sizeof(cpumask));
324			cpumask[sizeof(cpumask) - 1] = '\0';
325			maskset = 1;
326			printf("cpumask %s maskset %d\n", cpumask, maskset);
327			break;
328		case 't':
329			tid = atoi(optarg);
330			if (!tid)
331				err(1, "Invalid tgid\n");
332			cmd_type = TASKSTATS_CMD_ATTR_TGID;
333			break;
334		case 'p':
335			tid = atoi(optarg);
336			if (!tid)
337				err(1, "Invalid pid\n");
338			cmd_type = TASKSTATS_CMD_ATTR_PID;
339			break;
340		case 'c':
341
342			/* Block SIGCHLD for sigwait() later */
343			if (sigemptyset(&sigset) == -1)
344				err(1, "Failed to empty sigset");
345			if (sigaddset(&sigset, SIGCHLD))
346				err(1, "Failed to set sigchld in sigset");
347			sigprocmask(SIG_BLOCK, &sigset, NULL);
348
349			/* fork/exec a child */
350			tid = fork();
351			if (tid < 0)
352				err(1, "Fork failed\n");
353			if (tid == 0)
354				if (execvp(argv[optind - 1],
355				    &argv[optind - 1]) < 0)
356					exit(-1);
357
358			/* Set the command type and avoid further processing */
359			cmd_type = TASKSTATS_CMD_ATTR_PID;
360			forking = 1;
361			break;
362		case 'v':
363			printf("debug on\n");
364			dbg = 1;
365			break;
366		case 'l':
367			printf("listen forever\n");
368			loop = 1;
369			break;
370		default:
371			usage();
372			exit(-1);
373		}
374	}
375
376	if (write_file) {
377		fd = open(logfile, O_WRONLY | O_CREAT | O_TRUNC,
378			  S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
379		if (fd == -1) {
380			perror("Cannot open output file\n");
381			exit(1);
382		}
383	}
384
385	nl_sd = create_nl_socket(NETLINK_GENERIC);
386	if (nl_sd < 0)
387		err(1, "error creating Netlink socket\n");
388
389
390	mypid = getpid();
391	id = get_family_id(nl_sd);
392	if (!id) {
393		fprintf(stderr, "Error getting family id, errno %d\n", errno);
394		goto err;
395	}
396	PRINTF("family id %d\n", id);
397
398	if (maskset) {
399		rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
400			      TASKSTATS_CMD_ATTR_REGISTER_CPUMASK,
401			      &cpumask, strlen(cpumask) + 1);
402		PRINTF("Sent register cpumask, retval %d\n", rc);
403		if (rc < 0) {
404			fprintf(stderr, "error sending register cpumask\n");
405			goto err;
406		}
407	}
408
409	if (tid && containerset) {
410		fprintf(stderr, "Select either -t or -C, not both\n");
411		goto err;
412	}
413
414	/*
415	 * If we forked a child, wait for it to exit. Cannot use waitpid()
416	 * as all the delicious data would be reaped as part of the wait
417	 */
418	if (tid && forking) {
419		int sig_received;
420		sigwait(&sigset, &sig_received);
421	}
422
423	if (tid) {
424		rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
425			      cmd_type, &tid, sizeof(__u32));
426		PRINTF("Sent pid/tgid, retval %d\n", rc);
427		if (rc < 0) {
428			fprintf(stderr, "error sending tid/tgid cmd\n");
429			goto done;
430		}
431	}
432
433	if (containerset) {
434		cfd = open(containerpath, O_RDONLY);
435		if (cfd < 0) {
436			perror("error opening container file");
437			goto err;
438		}
439		rc = send_cmd(nl_sd, id, mypid, CGROUPSTATS_CMD_GET,
440			      CGROUPSTATS_CMD_ATTR_FD, &cfd, sizeof(__u32));
441		if (rc < 0) {
442			perror("error sending cgroupstats command");
443			goto err;
444		}
445	}
446	if (!maskset && !tid && !containerset) {
447		usage();
448		goto err;
449	}
450
451	do {
452		rep_len = recv(nl_sd, &msg, sizeof(msg), 0);
453		PRINTF("received %d bytes\n", rep_len);
454
455		if (rep_len < 0) {
456			fprintf(stderr, "nonfatal reply error: errno %d\n",
457				errno);
458			continue;
459		}
460		if (msg.n.nlmsg_type == NLMSG_ERROR ||
461		    !NLMSG_OK((&msg.n), rep_len)) {
462			struct nlmsgerr *err = NLMSG_DATA(&msg);
463			fprintf(stderr, "fatal reply error,  errno %d\n",
464				err->error);
465			goto done;
466		}
467
468		PRINTF("nlmsghdr size=%zu, nlmsg_len=%d, rep_len=%d\n",
469		       sizeof(struct nlmsghdr), msg.n.nlmsg_len, rep_len);
470
471
472		rep_len = GENLMSG_PAYLOAD(&msg.n);
473
474		na = (struct nlattr *) GENLMSG_DATA(&msg);
475		len = 0;
476		while (len < rep_len) {
477			len += NLA_ALIGN(na->nla_len);
478			switch (na->nla_type) {
479			case TASKSTATS_TYPE_AGGR_TGID:
480				/* Fall through */
481			case TASKSTATS_TYPE_AGGR_PID:
482				aggr_len = NLA_PAYLOAD(na->nla_len);
483				len2 = 0;
484				/* For nested attributes, na follows */
485				na = (struct nlattr *) NLA_DATA(na);
486				done = 0;
487				while (len2 < aggr_len) {
488					switch (na->nla_type) {
489					case TASKSTATS_TYPE_PID:
490						rtid = *(int *) NLA_DATA(na);
491						if (print_delays)
492							printf("PID\t%d\n", rtid);
493						break;
494					case TASKSTATS_TYPE_TGID:
495						rtid = *(int *) NLA_DATA(na);
496						if (print_delays)
497							printf("TGID\t%d\n", rtid);
498						break;
499					case TASKSTATS_TYPE_STATS:
500						count++;
501						if (print_delays)
502							print_delayacct((struct taskstats *) NLA_DATA(na));
503						if (print_io_accounting)
504							print_ioacct((struct taskstats *) NLA_DATA(na));
505						if (print_task_context_switch_counts)
506							task_context_switch_counts((struct taskstats *) NLA_DATA(na));
507						if (fd) {
508							if (write(fd, NLA_DATA(na), na->nla_len) < 0) {
509								err(1,"write error\n");
510							}
511						}
512						if (!loop)
513							goto done;
514						break;
515					case TASKSTATS_TYPE_NULL:
516						break;
517					default:
518						fprintf(stderr, "Unknown nested"
519							" nla_type %d\n",
520							na->nla_type);
521						break;
522					}
523					len2 += NLA_ALIGN(na->nla_len);
524					na = (struct nlattr *)((char *)na +
525							       NLA_ALIGN(na->nla_len));
526				}
527				break;
528
529			case CGROUPSTATS_TYPE_CGROUP_STATS:
530				print_cgroupstats(NLA_DATA(na));
531				break;
532			default:
533				fprintf(stderr, "Unknown nla_type %d\n",
534					na->nla_type);
535			case TASKSTATS_TYPE_NULL:
536				break;
537			}
538			na = (struct nlattr *) (GENLMSG_DATA(&msg) + len);
539		}
540	} while (loop);
541done:
542	if (maskset) {
543		rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
544			      TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK,
545			      &cpumask, strlen(cpumask) + 1);
546		printf("Sent deregister mask, retval %d\n", rc);
547		if (rc < 0)
548			err(rc, "error sending deregister cpumask\n");
549	}
550err:
551	close(nl_sd);
552	if (fd)
553		close(fd);
554	if (cfd)
555		close(cfd);
556	return 0;
557}
558