tools/accounting/getdelays.c

Source file repositories/reference/linux-study-clean/tools/accounting/getdelays.c

File Facts

System
Linux kernel
Corpus path
tools/accounting/getdelays.c
Extension
.c
Size
20533 bytes
Lines
767
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

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 recv_taskstats_msg(int sd, struct msgtemplate *msg)
{
	struct sockaddr_nl nladdr;
	struct iovec iov = {
		.iov_base = msg,
		.iov_len = sizeof(*msg),
	};
	struct msghdr hdr = {
		.msg_name = &nladdr,
		.msg_namelen = sizeof(nladdr),
		.msg_iov = &iov,
		.msg_iovlen = 1,
	};
	int ret;

	ret = recvmsg(sd, &hdr, 0);
	if (ret < 0)
		return -1;
	if (hdr.msg_flags & MSG_TRUNC) {
		errno = EMSGSIZE;
		return -1;
	}

	return ret;
}


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);

Annotation

Implementation Notes