linux-stable-rt/Documentation/accounting/getdelays.c

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/* 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
*
*/
#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/types.h>
#include <signal.h>
#include <linux/genetlink.h>
#include <linux/taskstats.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 { printf(fmt, ##arg); exit(code); } while (0)
int done = 0;
/*
* Create a raw netlink socket and bind
*/
static int create_nl_socket(int protocol, int groups)
{
socklen_t addr_len;
int fd;
struct sockaddr_nl local;
fd = socket(AF_NETLINK, SOCK_RAW, protocol);
if (fd < 0)
return -1;
memset(&local, 0, sizeof(local));
local.nl_family = AF_NETLINK;
local.nl_groups = groups;
if (bind(fd, (struct sockaddr *) &local, sizeof(local)) < 0)
goto error;
return fd;
error:
close(fd);
return -1;
}
int sendto_fd(int s, const char *buf, int bufLen)
{
struct sockaddr_nl nladdr;
int r;
memset(&nladdr, 0, sizeof(nladdr));
nladdr.nl_family = AF_NETLINK;
while ((r = sendto(s, 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
*/
int get_family_id(int sd)
{
struct {
struct nlmsghdr n;
struct genlmsghdr g;
char buf[256];
} family_req;
struct {
struct nlmsghdr n;
struct genlmsghdr g;
char buf[256];
} ans;
int id;
struct nlattr *na;
int rep_len;
/* Get family name */
family_req.n.nlmsg_type = GENL_ID_CTRL;
family_req.n.nlmsg_flags = NLM_F_REQUEST;
family_req.n.nlmsg_seq = 0;
family_req.n.nlmsg_pid = getpid();
family_req.n.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
family_req.g.cmd = CTRL_CMD_GETFAMILY;
family_req.g.version = 0x1;
na = (struct nlattr *) GENLMSG_DATA(&family_req);
na->nla_type = CTRL_ATTR_FAMILY_NAME;
na->nla_len = strlen(TASKSTATS_GENL_NAME) + 1 + NLA_HDRLEN;
strcpy(NLA_DATA(na), TASKSTATS_GENL_NAME);
family_req.n.nlmsg_len += NLMSG_ALIGN(na->nla_len);
if (sendto_fd(sd, (char *) &family_req, family_req.n.nlmsg_len) < 0)
err(1, "error sending message via Netlink\n");
rep_len = recv(sd, &ans, sizeof(ans), 0);
if (rep_len < 0)
err(1, "error receiving reply message via Netlink\n");
/* Validate response message */
if (!NLMSG_OK((&ans.n), rep_len))
err(1, "invalid reply message received via Netlink\n");
if (ans.n.nlmsg_type == NLMSG_ERROR) { /* error */
printf("error received NACK - leaving\n");
exit(1);
}
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;
}
void print_taskstats(struct taskstats *t)
{
printf("\n\nCPU %15s%15s%15s%15s\n"
" %15llu%15llu%15llu%15llu\n"
"IO %15s%15s\n"
" %15llu%15llu\n"
"MEM %15s%15s\n"
" %15llu%15llu\n\n",
"count", "real total", "virtual total", "delay total",
t->cpu_count, t->cpu_run_real_total, t->cpu_run_virtual_total,
t->cpu_delay_total,
"count", "delay total",
t->blkio_count, t->blkio_delay_total,
"count", "delay total", t->swapin_count, t->swapin_delay_total);
}
void sigchld(int sig)
{
done = 1;
}
int main(int argc, char *argv[])
{
int rc;
int sk_nl;
struct nlmsghdr *nlh;
struct genlmsghdr *genlhdr;
char *buf;
struct taskstats_cmd_param *param;
__u16 id;
struct nlattr *na;
/* For receiving */
struct sockaddr_nl kern_nla, from_nla;
socklen_t from_nla_len;
int recv_len;
struct taskstats_reply *reply;
struct {
struct nlmsghdr n;
struct genlmsghdr g;
char buf[256];
} req;
struct {
struct nlmsghdr n;
struct genlmsghdr g;
char buf[256];
} ans;
int nl_sd = -1;
int rep_len;
int len = 0;
int aggr_len, len2;
struct sockaddr_nl nladdr;
pid_t tid = 0;
pid_t rtid = 0;
int cmd_type = TASKSTATS_TYPE_TGID;
int c, status;
int forking = 0;
struct sigaction act = {
.sa_handler = SIG_IGN,
.sa_mask = SA_NOMASK,
};
struct sigaction tact ;
if (argc < 3) {
printf("usage %s [-t tgid][-p pid][-c cmd]\n", argv[0]);
exit(-1);
}
tact.sa_handler = sigchld;
sigemptyset(&tact.sa_mask);
if (sigaction(SIGCHLD, &tact, NULL) < 0)
err(1, "sigaction failed for SIGCHLD\n");
while (1) {
c = getopt(argc, argv, "t:p:c:");
if (c < 0)
break;
switch (c) {
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_TGID;
break;
case 'c':
opterr = 0;
tid = fork();
if (tid < 0)
err(1, "fork failed\n");
if (tid == 0) { /* child process */
if (execvp(argv[optind - 1], &argv[optind - 1]) < 0) {
exit(-1);
}
}
forking = 1;
break;
default:
printf("usage %s [-t tgid][-p pid][-c cmd]\n", argv[0]);
exit(-1);
break;
}
if (c == 'c')
break;
}
/* Construct Netlink request message */
/* Send Netlink request message & get reply */
if ((nl_sd =
create_nl_socket(NETLINK_GENERIC, TASKSTATS_LISTEN_GROUP)) < 0)
err(1, "error creating Netlink socket\n");
id = get_family_id(nl_sd);
/* Send command needed */
req.n.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
req.n.nlmsg_type = id;
req.n.nlmsg_flags = NLM_F_REQUEST;
req.n.nlmsg_seq = 0;
req.n.nlmsg_pid = tid;
req.g.cmd = TASKSTATS_CMD_GET;
na = (struct nlattr *) GENLMSG_DATA(&req);
na->nla_type = cmd_type;
na->nla_len = sizeof(unsigned int) + NLA_HDRLEN;
*(__u32 *) NLA_DATA(na) = tid;
req.n.nlmsg_len += NLMSG_ALIGN(na->nla_len);
if (!forking && sendto_fd(nl_sd, (char *) &req, req.n.nlmsg_len) < 0)
err(1, "error sending message via Netlink\n");
act.sa_handler = SIG_IGN;
sigemptyset(&act.sa_mask);
if (sigaction(SIGINT, &act, NULL) < 0)
err(1, "sigaction failed for SIGINT\n");
do {
int i;
struct pollfd pfd;
int pollres;
pfd.events = 0xffff & ~POLLOUT;
pfd.fd = nl_sd;
pollres = poll(&pfd, 1, 5000);
if (pollres < 0 || done) {
break;
}
rep_len = recv(nl_sd, &ans, sizeof(ans), 0);
nladdr.nl_family = AF_NETLINK;
nladdr.nl_groups = TASKSTATS_LISTEN_GROUP;
if (ans.n.nlmsg_type == NLMSG_ERROR) { /* error */
printf("error received NACK - leaving\n");
exit(1);
}
if (rep_len < 0) {
err(1, "error receiving reply message via Netlink\n");
break;
}
/* Validate response message */
if (!NLMSG_OK((&ans.n), rep_len))
err(1, "invalid reply message received via Netlink\n");
rep_len = GENLMSG_PAYLOAD(&ans.n);
na = (struct nlattr *) GENLMSG_DATA(&ans);
len = 0;
i = 0;
while (len < rep_len) {
len += NLA_ALIGN(na->nla_len);
switch (na->nla_type) {
case TASKSTATS_TYPE_AGGR_PID:
/* Fall through */
case TASKSTATS_TYPE_AGGR_TGID:
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);
break;
case TASKSTATS_TYPE_TGID:
rtid = *(int *) NLA_DATA(na);
break;
case TASKSTATS_TYPE_STATS:
if (rtid == tid) {
print_taskstats((struct taskstats *)
NLA_DATA(na));
done = 1;
}
break;
}
len2 += NLA_ALIGN(na->nla_len);
na = (struct nlattr *) ((char *) na + len2);
if (done)
break;
}
}
na = (struct nlattr *) (GENLMSG_DATA(&ans) + len);
if (done)
break;
}
if (done)
break;
}
while (1);
close(nl_sd);
return 0;
}