getdelays.c

  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 rcvbufsz;
 49char name[100];
 50int dbg;
 51int print_delays;
 52int print_io_accounting;
 53int print_task_context_switch_counts;
 54
 55#define PRINTF(fmt, arg...) {			\
 56	    if (dbg) {				\
 57		printf(fmt, ##arg);		\
 58	    }					\
 59	}
 60
 61/* Maximum size of response requested or message sent */
 62#define MAX_MSG_SIZE	1024
 63/* Maximum number of cpus expected to be specified in a cpumask */
 64#define MAX_CPUS	32
 65
 66struct msgtemplate {
 67	struct nlmsghdr n;
 68	struct genlmsghdr g;
 69	char buf[MAX_MSG_SIZE];
 70};
 71
 72char cpumask[100+6*MAX_CPUS];
 73
 74static void usage(void)
 75{
 76	fprintf(stderr, "getdelays [-dilv] [-w logfile] [-r bufsize] "
 77			"[-m cpumask] [-t tgid] [-p pid]\n");
 78	fprintf(stderr, "  -d: print delayacct stats\n");
 79	fprintf(stderr, "  -i: print IO accounting (works only with -p)\n");
 80	fprintf(stderr, "  -l: listen forever\n");
 81	fprintf(stderr, "  -v: debug on\n");
 82	fprintf(stderr, "  -C: container path\n");
 83}
 84
 85/*
 86 * Create a raw netlink socket and bind
 87 */
 88static int create_nl_socket(int protocol)
 89{
 90	int fd;
 91	struct sockaddr_nl local;
 92
 93	fd = socket(AF_NETLINK, SOCK_RAW, protocol);
 94	if (fd < 0)
 95		return -1;
 96
 97	if (rcvbufsz)
 98		if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF,
 99				&rcvbufsz, sizeof(rcvbufsz)) < 0) {
100			fprintf(stderr, "Unable to set socket rcv buf size to %d\n",
101				rcvbufsz);
102			goto error;
103		}
104
105	memset(&local, 0, sizeof(local));
106	local.nl_family = AF_NETLINK;
107
108	if (bind(fd, (struct sockaddr *) &local, sizeof(local)) < 0)
109		goto error;
110
111	return fd;
112error:
113	close(fd);
114	return -1;
115}
116
117
118static int send_cmd(int sd, __u16 nlmsg_type, __u32 nlmsg_pid,
119	     __u8 genl_cmd, __u16 nla_type,
120	     void *nla_data, int nla_len)
121{
122	struct nlattr *na;
123	struct sockaddr_nl nladdr;
124	int r, buflen;
125	char *buf;
126
127	struct msgtemplate msg;
128
129	msg.n.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
130	msg.n.nlmsg_type = nlmsg_type;
131	msg.n.nlmsg_flags = NLM_F_REQUEST;
132	msg.n.nlmsg_seq = 0;
133	msg.n.nlmsg_pid = nlmsg_pid;
134	msg.g.cmd = genl_cmd;
135	msg.g.version = 0x1;
136	na = (struct nlattr *) GENLMSG_DATA(&msg);
137	na->nla_type = nla_type;
138	na->nla_len = nla_len + NLA_HDRLEN;
139	memcpy(NLA_DATA(na), nla_data, nla_len);
140	msg.n.nlmsg_len += NLMSG_ALIGN(na->nla_len);
141
142	buf = (char *) &msg;
143	buflen = msg.n.nlmsg_len ;
144	memset(&nladdr, 0, sizeof(nladdr));
145	nladdr.nl_family = AF_NETLINK;
146	while ((r = sendto(sd, buf, buflen, 0, (struct sockaddr *) &nladdr,
147			   sizeof(nladdr))) < buflen) {
148		if (r > 0) {
149			buf += r;
150			buflen -= r;
151		} else if (errno != EAGAIN)
152			return -1;
153	}
154	return 0;
155}
156
157
158/*
159 * Probe the controller in genetlink to find the family id
160 * for the TASKSTATS family
161 */
162static int get_family_id(int sd)
163{
164	struct {
165		struct nlmsghdr n;
166		struct genlmsghdr g;
167		char buf[256];
168	} ans;
169
170	int id = 0, rc;
171	struct nlattr *na;
172	int rep_len;
173
174	strcpy(name, TASKSTATS_GENL_NAME);
175	rc = send_cmd(sd, GENL_ID_CTRL, getpid(), CTRL_CMD_GETFAMILY,
176			CTRL_ATTR_FAMILY_NAME, (void *)name,
177			strlen(TASKSTATS_GENL_NAME)+1);
178	if (rc < 0)
179		return 0;	/* sendto() failure? */
180
181	rep_len = recv(sd, &ans, sizeof(ans), 0);
182	if (ans.n.nlmsg_type == NLMSG_ERROR ||
183	    (rep_len < 0) || !NLMSG_OK((&ans.n), rep_len))
184		return 0;
185
186	na = (struct nlattr *) GENLMSG_DATA(&ans);
187	na = (struct nlattr *) ((char *) na + NLA_ALIGN(na->nla_len));
188	if (na->nla_type == CTRL_ATTR_FAMILY_ID) {
189		id = *(__u16 *) NLA_DATA(na);
190	}
191	return id;
192}
193
194#define average_ms(t, c) (t / 1000000ULL / (c ? c : 1))
195#define delay_ms(t) (t / 1000000ULL)
196
197/*
198 * Version compatibility note:
199 * Field availability depends on taskstats version (t->version),
200 * corresponding to TASKSTATS_VERSION in kernel headers
201 * see include/uapi/linux/taskstats.h
202 *
203 * Version feature mapping:
204 * version >= 11  - supports COMPACT statistics
205 * version >= 13  - supports WPCOPY statistics
206 * version >= 14  - supports IRQ statistics
207 * version >= 16  - supports *_max and *_min delay statistics
208 *
209 * Always verify version before accessing version-dependent fields
210 * to maintain backward compatibility.
211 */
212#define PRINT_CPU_DELAY(version, t) \
213	do { \
214		if (version >= 16) { \
215			printf("%-10s%15s%15s%15s%15s%15s%15s%15s\n", \
216				"CPU", "count", "real total", "virtual total", \
217				"delay total", "delay average", "delay max", "delay min"); \
218			printf("          %15llu%15llu%15llu%15llu%15.3fms%13.6fms%13.6fms\n", \
219				(unsigned long long)(t)->cpu_count, \
220				(unsigned long long)(t)->cpu_run_real_total, \
221				(unsigned long long)(t)->cpu_run_virtual_total, \
222				(unsigned long long)(t)->cpu_delay_total, \
223				average_ms((double)(t)->cpu_delay_total, (t)->cpu_count), \
224				delay_ms((double)(t)->cpu_delay_max), \
225				delay_ms((double)(t)->cpu_delay_min)); \
226		} else { \
227			printf("%-10s%15s%15s%15s%15s%15s\n", \
228				"CPU", "count", "real total", "virtual total", \
229				"delay total", "delay average"); \
230			printf("          %15llu%15llu%15llu%15llu%15.3fms\n", \
231				(unsigned long long)(t)->cpu_count, \
232				(unsigned long long)(t)->cpu_run_real_total, \
233				(unsigned long long)(t)->cpu_run_virtual_total, \
234				(unsigned long long)(t)->cpu_delay_total, \
235				average_ms((double)(t)->cpu_delay_total, (t)->cpu_count)); \
236		} \
237	} while (0)
238#define PRINT_FILED_DELAY(name, version, t, count, total, max, min) \
239	do { \
240		if (version >= 16) { \
241			printf("%-10s%15s%15s%15s%15s%15s\n", \
242				name, "count", "delay total", "delay average", \
243				"delay max", "delay min"); \
244			printf("          %15llu%15llu%15.3fms%13.6fms%13.6fms\n", \
245				(unsigned long long)(t)->count, \
246				(unsigned long long)(t)->total, \
247				average_ms((double)(t)->total, (t)->count), \
248				delay_ms((double)(t)->max), \
249				delay_ms((double)(t)->min)); \
250		} else { \
251			printf("%-10s%15s%15s%15s\n", \
252				name, "count", "delay total", "delay average"); \
253			printf("          %15llu%15llu%15.3fms\n", \
254				(unsigned long long)(t)->count, \
255				(unsigned long long)(t)->total, \
256				average_ms((double)(t)->total, (t)->count)); \
257		} \
258	} while (0)
259
260static void print_delayacct(struct taskstats *t)
261{
262	printf("\n\n");
263
264	PRINT_CPU_DELAY(t->version, t);
265
266	PRINT_FILED_DELAY("IO", t->version, t,
267		blkio_count, blkio_delay_total,
268		blkio_delay_max, blkio_delay_min);
269
270	PRINT_FILED_DELAY("SWAP", t->version, t,
271		swapin_count, swapin_delay_total,
272		swapin_delay_max, swapin_delay_min);
273
274	PRINT_FILED_DELAY("RECLAIM", t->version, t,
275		freepages_count, freepages_delay_total,
276		freepages_delay_max, freepages_delay_min);
277
278	PRINT_FILED_DELAY("THRASHING", t->version, t,
279		thrashing_count, thrashing_delay_total,
280		thrashing_delay_max, thrashing_delay_min);
281
282	if (t->version >= 11) {
283		PRINT_FILED_DELAY("COMPACT", t->version, t,
284			compact_count, compact_delay_total,
285			compact_delay_max, compact_delay_min);
286	}
287
288	if (t->version >= 13) {
289		PRINT_FILED_DELAY("WPCOPY", t->version, t,
290			wpcopy_count, wpcopy_delay_total,
291			wpcopy_delay_max, wpcopy_delay_min);
292	}
293
294	if (t->version >= 14) {
295		PRINT_FILED_DELAY("IRQ", t->version, t,
296			irq_count, irq_delay_total,
297			irq_delay_max, irq_delay_min);
298	}
299}
300
301static void task_context_switch_counts(struct taskstats *t)
302{
303	printf("\n\nTask   %15s%15s\n"
304	       "       %15llu%15llu\n",
305	       "voluntary", "nonvoluntary",
306	       (unsigned long long)t->nvcsw, (unsigned long long)t->nivcsw);
307}
308
309static void print_cgroupstats(struct cgroupstats *c)
310{
311	printf("sleeping %llu, blocked %llu, running %llu, stopped %llu, "
312		"uninterruptible %llu\n", (unsigned long long)c->nr_sleeping,
313		(unsigned long long)c->nr_io_wait,
314		(unsigned long long)c->nr_running,
315		(unsigned long long)c->nr_stopped,
316		(unsigned long long)c->nr_uninterruptible);
317}
318
319
320static void print_ioacct(struct taskstats *t)
321{
322	printf("%s: read=%llu, write=%llu, cancelled_write=%llu\n",
323		t->ac_comm,
324		(unsigned long long)t->read_bytes,
325		(unsigned long long)t->write_bytes,
326		(unsigned long long)t->cancelled_write_bytes);
327}
328
329int main(int argc, char *argv[])
330{
331	int c, rc, rep_len, aggr_len, len2;
332	int cmd_type = TASKSTATS_CMD_ATTR_UNSPEC;
333	__u16 id;
334	__u32 mypid;
335
336	struct nlattr *na;
337	int nl_sd = -1;
338	int len = 0;
339	pid_t tid = 0;
340	pid_t rtid = 0;
341
342	int fd = 0;
343	int write_file = 0;
344	int maskset = 0;
345	char *logfile = NULL;
346	int loop = 0;
347	int containerset = 0;
348	char *containerpath = NULL;
349	int cfd = 0;
350	int forking = 0;
351	sigset_t sigset;
352
353	struct msgtemplate msg;
354
355	while (!forking) {
356		c = getopt(argc, argv, "qdiw:r:m:t:p:vlC:c:");
357		if (c < 0)
358			break;
359
360		switch (c) {
361		case 'd':
362			printf("print delayacct stats ON\n");
363			print_delays = 1;
364			break;
365		case 'i':
366			printf("printing IO accounting\n");
367			print_io_accounting = 1;
368			break;
369		case 'q':
370			printf("printing task/process context switch rates\n");
371			print_task_context_switch_counts = 1;
372			break;
373		case 'C':
374			containerset = 1;
375			containerpath = optarg;
376			break;
377		case 'w':
378			logfile = strdup(optarg);
379			printf("write to file %s\n", logfile);
380			write_file = 1;
381			break;
382		case 'r':
383			rcvbufsz = atoi(optarg);
384			printf("receive buf size %d\n", rcvbufsz);
385			if (rcvbufsz < 0)
386				err(1, "Invalid rcv buf size\n");
387			break;
388		case 'm':
389			strncpy(cpumask, optarg, sizeof(cpumask));
390			cpumask[sizeof(cpumask) - 1] = '\0';
391			maskset = 1;
392			printf("cpumask %s maskset %d\n", cpumask, maskset);
393			break;
394		case 't':
395			tid = atoi(optarg);
396			if (!tid)
397				err(1, "Invalid tgid\n");
398			cmd_type = TASKSTATS_CMD_ATTR_TGID;
399			break;
400		case 'p':
401			tid = atoi(optarg);
402			if (!tid)
403				err(1, "Invalid pid\n");
404			cmd_type = TASKSTATS_CMD_ATTR_PID;
405			break;
406		case 'c':
407
408			/* Block SIGCHLD for sigwait() later */
409			if (sigemptyset(&sigset) == -1)
410				err(1, "Failed to empty sigset");
411			if (sigaddset(&sigset, SIGCHLD))
412				err(1, "Failed to set sigchld in sigset");
413			sigprocmask(SIG_BLOCK, &sigset, NULL);
414
415			/* fork/exec a child */
416			tid = fork();
417			if (tid < 0)
418				err(1, "Fork failed\n");
419			if (tid == 0)
420				if (execvp(argv[optind - 1],
421				    &argv[optind - 1]) < 0)
422					exit(-1);
423
424			/* Set the command type and avoid further processing */
425			cmd_type = TASKSTATS_CMD_ATTR_PID;
426			forking = 1;
427			break;
428		case 'v':
429			printf("debug on\n");
430			dbg = 1;
431			break;
432		case 'l':
433			printf("listen forever\n");
434			loop = 1;
435			break;
436		default:
437			usage();
438			exit(-1);
439		}
440	}
441
442	if (write_file) {
443		fd = open(logfile, O_WRONLY | O_CREAT | O_TRUNC,
444			  S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
445		if (fd == -1) {
446			perror("Cannot open output file\n");
447			exit(1);
448		}
449	}
450
451	nl_sd = create_nl_socket(NETLINK_GENERIC);
452	if (nl_sd < 0)
453		err(1, "error creating Netlink socket\n");
454
455
456	mypid = getpid();
457	id = get_family_id(nl_sd);
458	if (!id) {
459		fprintf(stderr, "Error getting family id, errno %d\n", errno);
460		goto err;
461	}
462	PRINTF("family id %d\n", id);
463
464	if (maskset) {
465		rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
466			      TASKSTATS_CMD_ATTR_REGISTER_CPUMASK,
467			      &cpumask, strlen(cpumask) + 1);
468		PRINTF("Sent register cpumask, retval %d\n", rc);
469		if (rc < 0) {
470			fprintf(stderr, "error sending register cpumask\n");
471			goto err;
472		}
473	}
474
475	if (tid && containerset) {
476		fprintf(stderr, "Select either -t or -C, not both\n");
477		goto err;
478	}
479
480	/*
481	 * If we forked a child, wait for it to exit. Cannot use waitpid()
482	 * as all the delicious data would be reaped as part of the wait
483	 */
484	if (tid && forking) {
485		int sig_received;
486		sigwait(&sigset, &sig_received);
487	}
488
489	if (tid) {
490		rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
491			      cmd_type, &tid, sizeof(__u32));
492		PRINTF("Sent pid/tgid, retval %d\n", rc);
493		if (rc < 0) {
494			fprintf(stderr, "error sending tid/tgid cmd\n");
495			goto done;
496		}
497	}
498
499	if (containerset) {
500		cfd = open(containerpath, O_RDONLY);
501		if (cfd < 0) {
502			perror("error opening container file");
503			goto err;
504		}
505		rc = send_cmd(nl_sd, id, mypid, CGROUPSTATS_CMD_GET,
506			      CGROUPSTATS_CMD_ATTR_FD, &cfd, sizeof(__u32));
507		if (rc < 0) {
508			perror("error sending cgroupstats command");
509			goto err;
510		}
511	}
512	if (!maskset && !tid && !containerset) {
513		usage();
514		goto err;
515	}
516
517	do {
518		rep_len = recv(nl_sd, &msg, sizeof(msg), 0);
519		PRINTF("received %d bytes\n", rep_len);
520
521		if (rep_len < 0) {
522			fprintf(stderr, "nonfatal reply error: errno %d\n",
523				errno);
524			continue;
525		}
526		if (msg.n.nlmsg_type == NLMSG_ERROR ||
527		    !NLMSG_OK((&msg.n), rep_len)) {
528			struct nlmsgerr *err = NLMSG_DATA(&msg);
529			fprintf(stderr, "fatal reply error,  errno %d\n",
530				err->error);
531			goto done;
532		}
533
534		PRINTF("nlmsghdr size=%zu, nlmsg_len=%d, rep_len=%d\n",
535		       sizeof(struct nlmsghdr), msg.n.nlmsg_len, rep_len);
536
537
538		rep_len = GENLMSG_PAYLOAD(&msg.n);
539
540		na = (struct nlattr *) GENLMSG_DATA(&msg);
541		len = 0;
542		while (len < rep_len) {
543			len += NLA_ALIGN(na->nla_len);
544			switch (na->nla_type) {
545			case TASKSTATS_TYPE_AGGR_TGID:
546				/* Fall through */
547			case TASKSTATS_TYPE_AGGR_PID:
548				aggr_len = NLA_PAYLOAD(na->nla_len);
549				len2 = 0;
550				/* For nested attributes, na follows */
551				na = (struct nlattr *) NLA_DATA(na);
552				while (len2 < aggr_len) {
553					switch (na->nla_type) {
554					case TASKSTATS_TYPE_PID:
555						rtid = *(int *) NLA_DATA(na);
556						if (print_delays)
557							printf("PID\t%d\n", rtid);
558						break;
559					case TASKSTATS_TYPE_TGID:
560						rtid = *(int *) NLA_DATA(na);
561						if (print_delays)
562							printf("TGID\t%d\n", rtid);
563						break;
564					case TASKSTATS_TYPE_STATS:
565						if (print_delays)
566							print_delayacct((struct taskstats *) NLA_DATA(na));
567						if (print_io_accounting)
568							print_ioacct((struct taskstats *) NLA_DATA(na));
569						if (print_task_context_switch_counts)
570							task_context_switch_counts((struct taskstats *) NLA_DATA(na));
571						if (fd) {
572							if (write(fd, NLA_DATA(na), na->nla_len) < 0) {
573								err(1,"write error\n");
574							}
575						}
576						if (!loop)
577							goto done;
578						break;
579					case TASKSTATS_TYPE_NULL:
580						break;
581					default:
582						fprintf(stderr, "Unknown nested"
583							" nla_type %d\n",
584							na->nla_type);
585						break;
586					}
587					len2 += NLA_ALIGN(na->nla_len);
588					na = (struct nlattr *)((char *)na +
589							       NLA_ALIGN(na->nla_len));
590				}
591				break;
592
593			case CGROUPSTATS_TYPE_CGROUP_STATS:
594				print_cgroupstats(NLA_DATA(na));
595				break;
596			default:
597				fprintf(stderr, "Unknown nla_type %d\n",
598					na->nla_type);
599			case TASKSTATS_TYPE_NULL:
600				break;
601			}
602			na = (struct nlattr *) (GENLMSG_DATA(&msg) + len);
603		}
604	} while (loop);
605done:
606	if (maskset) {
607		rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
608			      TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK,
609			      &cpumask, strlen(cpumask) + 1);
610		printf("Sent deregister mask, retval %d\n", rc);
611		if (rc < 0)
612			err(rc, "error sending deregister cpumask\n");
613	}
614err:
615	close(nl_sd);
616	if (fd)
617		close(fd);
618	if (cfd)
619		close(cfd);
620	return 0;
621}