linux/Documentation/accounting/getdelays.c
Nicolas Dichtel 570d8e9398 taskstats: fix nl parsing in accounting/getdelays.c
The type TASKSTATS_TYPE_NULL should always be ignored.

When jumping to the next attribute, only the length of the current
attribute should be added, not the length of all nested attributes.
This last bug was not visible before commit 80df554275, because the
kernel didn't put more than two nested attributes.

Fixes: a3baf649ca ("[PATCH] per-task-delay-accounting: documentation")
Fixes: 80df554275 ("taskstats: use the libnl API to align nlattr on 64-bit")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-27 12:50:14 -04:00

551 lines
13 KiB
C

/* 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;
#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);
goto error;
}
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 = NULL;
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;
containerpath = optarg;
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));
cpumask[sizeof(cpumask) - 1] = '\0';
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);
}
}
nl_sd = create_nl_socket(NETLINK_GENERIC);
if (nl_sd < 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;
case TASKSTATS_TYPE_NULL:
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 +
NLA_ALIGN(na->nla_len));
}
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;
}