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Based on kernel version 4.8. Page generated on 2016-10-06 23:09 EST.

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