Documentation / accounting / getdelays.c

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Based on kernel version 3.2. Page generated on 2012-01-05 23:27 EST.

	/* getdelays.c
	 *
	 * Utility to get per-pid and per-tgid delay accounting statistics
	 * Also illustrates usage of the taskstats interface
	 *
	 * Copyright (C) Shailabh Nagar, IBM Corp. 2005
	 * Copyright (C) Balbir Singh, IBM Corp. 2006
	 * Copyright (c) Jay Lan, SGI. 2006
	 *
	 * Compile with
	 *	gcc -I/usr/src/linux/include getdelays.c -o getdelays
	 */
	
	#include <stdio.h>
	#include <stdlib.h>
	#include <errno.h>
	#include <unistd.h>
	#include <poll.h>
	#include <string.h>
	#include <fcntl.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <sys/socket.h>
	#include <sys/wait.h>
	#include <signal.h>
	
	#include <linux/genetlink.h>
	#include <linux/taskstats.h>
	#include <linux/cgroupstats.h>
	
	/*
	 * Generic macros for dealing with netlink sockets. Might be duplicated
	 * elsewhere. It is recommended that commercial grade applications use
	 * libnl or libnetlink and use the interfaces provided by the library
	 */
	#define GENLMSG_DATA(glh)	((void *)(NLMSG_DATA(glh) + GENL_HDRLEN))
	#define GENLMSG_PAYLOAD(glh)	(NLMSG_PAYLOAD(glh, 0) - GENL_HDRLEN)
	#define NLA_DATA(na)		((void *)((char*)(na) + NLA_HDRLEN))
	#define NLA_PAYLOAD(len)	(len - NLA_HDRLEN)
	
	#define err(code, fmt, arg...)			\
		do {					\
			fprintf(stderr, fmt, ##arg);	\
			exit(code);			\
		} while (0)
	
	int done;
	int rcvbufsz;
	char name[100];
	int dbg;
	int print_delays;
	int print_io_accounting;
	int print_task_context_switch_counts;
	__u64 stime, utime;
	
	#define PRINTF(fmt, arg...) {			\
		    if (dbg) {				\
			printf(fmt, ##arg);		\
		    }					\
		}
	
	/* Maximum size of response requested or message sent */
	#define MAX_MSG_SIZE	1024
	/* Maximum number of cpus expected to be specified in a cpumask */
	#define MAX_CPUS	32
	
	struct msgtemplate {
		struct nlmsghdr n;
		struct genlmsghdr g;
		char buf[MAX_MSG_SIZE];
	};
	
	char cpumask[100+6*MAX_CPUS];
	
	static void usage(void)
	{
		fprintf(stderr, "getdelays [-dilv] [-w logfile] [-r bufsize] "
				"[-m cpumask] [-t tgid] [-p pid]\n");
		fprintf(stderr, "  -d: print delayacct stats\n");
		fprintf(stderr, "  -i: print IO accounting (works only with -p)\n");
		fprintf(stderr, "  -l: listen forever\n");
		fprintf(stderr, "  -v: debug on\n");
		fprintf(stderr, "  -C: container path\n");
	}
	
	/*
	 * Create a raw netlink socket and bind
	 */
	static int create_nl_socket(int protocol)
	{
		int fd;
		struct sockaddr_nl local;
	
		fd = socket(AF_NETLINK, SOCK_RAW, protocol);
		if (fd < 0)
			return -1;
	
		if (rcvbufsz)
			if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF,
					&rcvbufsz, sizeof(rcvbufsz)) < 0) {
				fprintf(stderr, "Unable to set socket rcv buf size "
						"to %d\n",
					rcvbufsz);
				return -1;
			}
	
		memset(&local, 0, sizeof(local));
		local.nl_family = AF_NETLINK;
	
		if (bind(fd, (struct sockaddr *) &local, sizeof(local)) < 0)
			goto error;
	
		return fd;
	error:
		close(fd);
		return -1;
	}
	
	
	static int send_cmd(int sd, __u16 nlmsg_type, __u32 nlmsg_pid,
		     __u8 genl_cmd, __u16 nla_type,
		     void *nla_data, int nla_len)
	{
		struct nlattr *na;
		struct sockaddr_nl nladdr;
		int r, buflen;
		char *buf;
	
		struct msgtemplate msg;
	
		msg.n.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
		msg.n.nlmsg_type = nlmsg_type;
		msg.n.nlmsg_flags = NLM_F_REQUEST;
		msg.n.nlmsg_seq = 0;
		msg.n.nlmsg_pid = nlmsg_pid;
		msg.g.cmd = genl_cmd;
		msg.g.version = 0x1;
		na = (struct nlattr *) GENLMSG_DATA(&msg);
		na->nla_type = nla_type;
		na->nla_len = nla_len + 1 + NLA_HDRLEN;
		memcpy(NLA_DATA(na), nla_data, nla_len);
		msg.n.nlmsg_len += NLMSG_ALIGN(na->nla_len);
	
		buf = (char *) &msg;
		buflen = msg.n.nlmsg_len ;
		memset(&nladdr, 0, sizeof(nladdr));
		nladdr.nl_family = AF_NETLINK;
		while ((r = sendto(sd, buf, buflen, 0, (struct sockaddr *) &nladdr,
				   sizeof(nladdr))) < buflen) {
			if (r > 0) {
				buf += r;
				buflen -= r;
			} else if (errno != EAGAIN)
				return -1;
		}
		return 0;
	}
	
	
	/*
	 * Probe the controller in genetlink to find the family id
	 * for the TASKSTATS family
	 */
	static int get_family_id(int sd)
	{
		struct {
			struct nlmsghdr n;
			struct genlmsghdr g;
			char buf[256];
		} ans;
	
		int id = 0, rc;
		struct nlattr *na;
		int rep_len;
	
		strcpy(name, TASKSTATS_GENL_NAME);
		rc = send_cmd(sd, GENL_ID_CTRL, getpid(), CTRL_CMD_GETFAMILY,
				CTRL_ATTR_FAMILY_NAME, (void *)name,
				strlen(TASKSTATS_GENL_NAME)+1);
		if (rc < 0)
			return 0;	/* sendto() failure? */
	
		rep_len = recv(sd, &ans, sizeof(ans), 0);
		if (ans.n.nlmsg_type == NLMSG_ERROR ||
		    (rep_len < 0) || !NLMSG_OK((&ans.n), rep_len))
			return 0;
	
		na = (struct nlattr *) GENLMSG_DATA(&ans);
		na = (struct nlattr *) ((char *) na + NLA_ALIGN(na->nla_len));
		if (na->nla_type == CTRL_ATTR_FAMILY_ID) {
			id = *(__u16 *) NLA_DATA(na);
		}
		return id;
	}
	
	#define average_ms(t, c) (t / 1000000ULL / (c ? c : 1))
	
	static void print_delayacct(struct taskstats *t)
	{
		printf("\n\nCPU   %15s%15s%15s%15s%15s\n"
		       "      %15llu%15llu%15llu%15llu%15.3fms\n"
		       "IO    %15s%15s%15s\n"
		       "      %15llu%15llu%15llums\n"
		       "SWAP  %15s%15s%15s\n"
		       "      %15llu%15llu%15llums\n"
		       "RECLAIM  %12s%15s%15s\n"
		       "      %15llu%15llu%15llums\n",
		       "count", "real total", "virtual total",
		       "delay total", "delay average",
		       (unsigned long long)t->cpu_count,
		       (unsigned long long)t->cpu_run_real_total,
		       (unsigned long long)t->cpu_run_virtual_total,
		       (unsigned long long)t->cpu_delay_total,
		       average_ms((double)t->cpu_delay_total, t->cpu_count),
		       "count", "delay total", "delay average",
		       (unsigned long long)t->blkio_count,
		       (unsigned long long)t->blkio_delay_total,
		       average_ms(t->blkio_delay_total, t->blkio_count),
		       "count", "delay total", "delay average",
		       (unsigned long long)t->swapin_count,
		       (unsigned long long)t->swapin_delay_total,
		       average_ms(t->swapin_delay_total, t->swapin_count),
		       "count", "delay total", "delay average",
		       (unsigned long long)t->freepages_count,
		       (unsigned long long)t->freepages_delay_total,
		       average_ms(t->freepages_delay_total, t->freepages_count));
	}
	
	static void task_context_switch_counts(struct taskstats *t)
	{
		printf("\n\nTask   %15s%15s\n"
		       "       %15llu%15llu\n",
		       "voluntary", "nonvoluntary",
		       (unsigned long long)t->nvcsw, (unsigned long long)t->nivcsw);
	}
	
	static void print_cgroupstats(struct cgroupstats *c)
	{
		printf("sleeping %llu, blocked %llu, running %llu, stopped %llu, "
			"uninterruptible %llu\n", (unsigned long long)c->nr_sleeping,
			(unsigned long long)c->nr_io_wait,
			(unsigned long long)c->nr_running,
			(unsigned long long)c->nr_stopped,
			(unsigned long long)c->nr_uninterruptible);
	}
	
	
	static void print_ioacct(struct taskstats *t)
	{
		printf("%s: read=%llu, write=%llu, cancelled_write=%llu\n",
			t->ac_comm,
			(unsigned long long)t->read_bytes,
			(unsigned long long)t->write_bytes,
			(unsigned long long)t->cancelled_write_bytes);
	}
	
	int main(int argc, char *argv[])
	{
		int c, rc, rep_len, aggr_len, len2;
		int cmd_type = TASKSTATS_CMD_ATTR_UNSPEC;
		__u16 id;
		__u32 mypid;
	
		struct nlattr *na;
		int nl_sd = -1;
		int len = 0;
		pid_t tid = 0;
		pid_t rtid = 0;
	
		int fd = 0;
		int count = 0;
		int write_file = 0;
		int maskset = 0;
		char *logfile = NULL;
		int loop = 0;
		int containerset = 0;
		char containerpath[1024];
		int cfd = 0;
		int forking = 0;
		sigset_t sigset;
	
		struct msgtemplate msg;
	
		while (!forking) {
			c = getopt(argc, argv, "qdiw:r:m:t:p:vlC:c:");
			if (c < 0)
				break;
	
			switch (c) {
			case 'd':
				printf("print delayacct stats ON\n");
				print_delays = 1;
				break;
			case 'i':
				printf("printing IO accounting\n");
				print_io_accounting = 1;
				break;
			case 'q':
				printf("printing task/process context switch rates\n");
				print_task_context_switch_counts = 1;
				break;
			case 'C':
				containerset = 1;
				strncpy(containerpath, optarg, strlen(optarg) + 1);
				break;
			case 'w':
				logfile = strdup(optarg);
				printf("write to file %s\n", logfile);
				write_file = 1;
				break;
			case 'r':
				rcvbufsz = atoi(optarg);
				printf("receive buf size %d\n", rcvbufsz);
				if (rcvbufsz < 0)
					err(1, "Invalid rcv buf size\n");
				break;
			case 'm':
				strncpy(cpumask, optarg, sizeof(cpumask));
				maskset = 1;
				printf("cpumask %s maskset %d\n", cpumask, maskset);
				break;
			case 't':
				tid = atoi(optarg);
				if (!tid)
					err(1, "Invalid tgid\n");
				cmd_type = TASKSTATS_CMD_ATTR_TGID;
				break;
			case 'p':
				tid = atoi(optarg);
				if (!tid)
					err(1, "Invalid pid\n");
				cmd_type = TASKSTATS_CMD_ATTR_PID;
				break;
			case 'c':
	
				/* Block SIGCHLD for sigwait() later */
				if (sigemptyset(&sigset) == -1)
					err(1, "Failed to empty sigset");
				if (sigaddset(&sigset, SIGCHLD))
					err(1, "Failed to set sigchld in sigset");
				sigprocmask(SIG_BLOCK, &sigset, NULL);
	
				/* fork/exec a child */
				tid = fork();
				if (tid < 0)
					err(1, "Fork failed\n");
				if (tid == 0)
					if (execvp(argv[optind - 1],
					    &argv[optind - 1]) < 0)
						exit(-1);
	
				/* Set the command type and avoid further processing */
				cmd_type = TASKSTATS_CMD_ATTR_PID;
				forking = 1;
				break;
			case 'v':
				printf("debug on\n");
				dbg = 1;
				break;
			case 'l':
				printf("listen forever\n");
				loop = 1;
				break;
			default:
				usage();
				exit(-1);
			}
		}
	
		if (write_file) {
			fd = open(logfile, O_WRONLY | O_CREAT | O_TRUNC,
				  S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
			if (fd == -1) {
				perror("Cannot open output file\n");
				exit(1);
			}
		}
	
		if ((nl_sd = create_nl_socket(NETLINK_GENERIC)) < 0)
			err(1, "error creating Netlink socket\n");
	
	
		mypid = getpid();
		id = get_family_id(nl_sd);
		if (!id) {
			fprintf(stderr, "Error getting family id, errno %d\n", errno);
			goto err;
		}
		PRINTF("family id %d\n", id);
	
		if (maskset) {
			rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
				      TASKSTATS_CMD_ATTR_REGISTER_CPUMASK,
				      &cpumask, strlen(cpumask) + 1);
			PRINTF("Sent register cpumask, retval %d\n", rc);
			if (rc < 0) {
				fprintf(stderr, "error sending register cpumask\n");
				goto err;
			}
		}
	
		if (tid && containerset) {
			fprintf(stderr, "Select either -t or -C, not both\n");
			goto err;
		}
	
		/*
		 * If we forked a child, wait for it to exit. Cannot use waitpid()
		 * as all the delicious data would be reaped as part of the wait
		 */
		if (tid && forking) {
			int sig_received;
			sigwait(&sigset, &sig_received);
		}
	
		if (tid) {
			rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
				      cmd_type, &tid, sizeof(__u32));
			PRINTF("Sent pid/tgid, retval %d\n", rc);
			if (rc < 0) {
				fprintf(stderr, "error sending tid/tgid cmd\n");
				goto done;
			}
		}
	
		if (containerset) {
			cfd = open(containerpath, O_RDONLY);
			if (cfd < 0) {
				perror("error opening container file");
				goto err;
			}
			rc = send_cmd(nl_sd, id, mypid, CGROUPSTATS_CMD_GET,
				      CGROUPSTATS_CMD_ATTR_FD, &cfd, sizeof(__u32));
			if (rc < 0) {
				perror("error sending cgroupstats command");
				goto err;
			}
		}
		if (!maskset && !tid && !containerset) {
			usage();
			goto err;
		}
	
		do {
			rep_len = recv(nl_sd, &msg, sizeof(msg), 0);
			PRINTF("received %d bytes\n", rep_len);
	
			if (rep_len < 0) {
				fprintf(stderr, "nonfatal reply error: errno %d\n",
					errno);
				continue;
			}
			if (msg.n.nlmsg_type == NLMSG_ERROR ||
			    !NLMSG_OK((&msg.n), rep_len)) {
				struct nlmsgerr *err = NLMSG_DATA(&msg);
				fprintf(stderr, "fatal reply error,  errno %d\n",
					err->error);
				goto done;
			}
	
			PRINTF("nlmsghdr size=%zu, nlmsg_len=%d, rep_len=%d\n",
			       sizeof(struct nlmsghdr), msg.n.nlmsg_len, rep_len);
	
	
			rep_len = GENLMSG_PAYLOAD(&msg.n);
	
			na = (struct nlattr *) GENLMSG_DATA(&msg);
			len = 0;
			while (len < rep_len) {
				len += NLA_ALIGN(na->nla_len);
				switch (na->nla_type) {
				case TASKSTATS_TYPE_AGGR_TGID:
					/* Fall through */
				case TASKSTATS_TYPE_AGGR_PID:
					aggr_len = NLA_PAYLOAD(na->nla_len);
					len2 = 0;
					/* For nested attributes, na follows */
					na = (struct nlattr *) NLA_DATA(na);
					done = 0;
					while (len2 < aggr_len) {
						switch (na->nla_type) {
						case TASKSTATS_TYPE_PID:
							rtid = *(int *) NLA_DATA(na);
							if (print_delays)
								printf("PID\t%d\n", rtid);
							break;
						case TASKSTATS_TYPE_TGID:
							rtid = *(int *) NLA_DATA(na);
							if (print_delays)
								printf("TGID\t%d\n", rtid);
							break;
						case TASKSTATS_TYPE_STATS:
							count++;
							if (print_delays)
								print_delayacct((struct taskstats *) NLA_DATA(na));
							if (print_io_accounting)
								print_ioacct((struct taskstats *) NLA_DATA(na));
							if (print_task_context_switch_counts)
								task_context_switch_counts((struct taskstats *) NLA_DATA(na));
							if (fd) {
								if (write(fd, NLA_DATA(na), na->nla_len) < 0) {
									err(1,"write error\n");
								}
							}
							if (!loop)
								goto done;
							break;
						default:
							fprintf(stderr, "Unknown nested"
								" nla_type %d\n",
								na->nla_type);
							break;
						}
						len2 += NLA_ALIGN(na->nla_len);
						na = (struct nlattr *) ((char *) na + len2);
					}
					break;
	
				case CGROUPSTATS_TYPE_CGROUP_STATS:
					print_cgroupstats(NLA_DATA(na));
					break;
				default:
					fprintf(stderr, "Unknown nla_type %d\n",
						na->nla_type);
				case TASKSTATS_TYPE_NULL:
					break;
				}
				na = (struct nlattr *) (GENLMSG_DATA(&msg) + len);
			}
		} while (loop);
	done:
		if (maskset) {
			rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
				      TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK,
				      &cpumask, strlen(cpumask) + 1);
			printf("Sent deregister mask, retval %d\n", rc);
			if (rc < 0)
				err(rc, "error sending deregister cpumask\n");
		}
	err:
		close(nl_sd);
		if (fd)
			close(fd);
		if (cfd)
			close(cfd);
		return 0;
	}

• [ accounting ]
• cgroupstats.txt
• delay-accounting.txt
• getdelays.c
• Makefile
• taskstats-struct.txt
• taskstats.txt
•