taskstats: version 12 with thread group and exe info

The task exit struct needs some crucial information to be able to provide
an enhanced version of process and thread accounting.  This change
provides:

1. ac_tgid in additon to ac_pid
2. thread group execution walltime in ac_tgetime
3. flag AGROUP in ac_flag to indicate the last task
   in a thread group / process
4. device ID and inode of task's /proc/self/exe in
   ac_exe_dev and ac_exe_inode
5. tools/accounting/procacct as demonstrator

When a task exits, taskstats are reported to userspace including the
task's pid and ppid, but without the id of the thread group this task is
part of.  Without the tgid, the stats of single tasks cannot be correlated
to each other as a thread group (process).

The taskstats documentation suggests that on process exit a data set
consisting of accumulated stats for the whole group is produced.  But such
an additional set of stats is only produced for actually multithreaded
processes, not groups that had only one thread, and also those stats only
contain data about delay accounting and not the more basic information
about CPU and memory resource usage.  Adding the AGROUP flag to be set
when the last task of a group exited enables determination of process end
also for single-threaded processes.

My applicaton basically does enhanced process accounting with summed
cputime, biggest maxrss, tasks per process.  The data is not available
with the traditional BSD process accounting (which is not designed to be
extensible) and the taskstats interface allows more efficient on-the-fly
grouping and summing of the stats, anyway, without intermediate disk
writes.

Furthermore, I do carry statistics on which exact program binary is used
how often with associated resources, getting a picture on how important
which parts of a collection of installed scientific software in different
versions are, and how well they put load on the machine.  This is enabled
by providing information on /proc/self/exe for each task.  I assume the
two 64-bit fields for device ID and inode are more appropriate than the
possibly large resolved path to keep the data volume down.

Add the tgid to the stats to complete task identification, the flag AGROUP
to mark the last task of a group, the group wallclock time, and
inode-based identification of the associated executable file.

Add tools/accounting/procacct.c as a simplified fork of getdelays.c to
demonstrate process and thread accounting.

[thomas.orgis@uni-hamburg.de: fix version number in comment]
  Link: https://lkml.kernel.org/r/20220405003601.7a5f6008@plasteblaster
Link: https://lkml.kernel.org/r/20220331004106.64e5616b@plasteblaster
Signed-off-by: Dr. Thomas Orgis <thomas.orgis@uni-hamburg.de>
Reviewed-by: Ismael Luceno <ismael@iodev.co.uk>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

3 files changed, 419 insertions, 1 deletions

diff --git a/tools/accounting/.gitignore b/tools/accounting/.gitignore
index c45fb4ed4309..522a690aaf3d 100644
--- a/tools/accounting/.gitignore
+++ b/tools/accounting/.gitignore
@@ -1,2 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0-only
 getdelays
+procacct
diff --git a/tools/accounting/Makefile b/tools/accounting/Makefile
index 03687f19cbb1..11def1ad046c 100644
--- a/tools/accounting/Makefile
+++ b/tools/accounting/Makefile
@@ -2,7 +2,7 @@
 CC := $(CROSS_COMPILE)gcc
 CFLAGS := -I../../usr/include
 
-PROGS := getdelays
+PROGS := getdelays procacct
 
 all: $(PROGS)
 
diff --git a/tools/accounting/procacct.c b/tools/accounting/procacct.c
new file mode 100644
index 000000000000..8353d3237e50
--- /dev/null
+++ b/tools/accounting/procacct.c
@@ -0,0 +1,417 @@
+// SPDX-License-Identifier: GPL-2.0
+/* procacct.c
+ *
+ * Demonstrator of fetching resource data on task exit, as a way
+ * to accumulate accurate program resource usage statistics, without
+ * prior identification of the programs. For that, the fields for
+ * device and inode of the program executable binary file are also
+ * extracted in addition to the command string.
+ *
+ * The TGID together with the PID and the AGROUP flag allow
+ * identification of threads in a process and single-threaded processes.
+ * The ac_tgetime field gives proper whole-process walltime.
+ *
+ * Written (changed) by Thomas Orgis, University of Hamburg in 2022
+ *
+ * This is a cheap derivation (inheriting the style) of 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
+ */
+
+#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/acct.h>
+#include <linux/taskstats.h>
+#include <linux/kdev_t.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 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, "procacct [-v] [-w logfile] [-r bufsize] [-m cpumask]\n");
+	fprintf(stderr, "  -v: debug on\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_procacct(struct taskstats *t)
+{
+	/* First letter: T is a mere thread, G the last in a group, U  unknown. */
+	printf(
+		"%c pid=%lu tgid=%lu uid=%lu wall=%llu gwall=%llu cpu=%llu vmpeak=%llu rsspeak=%llu dev=%lu:%lu inode=%llu comm=%s\n"
+	,	t->version >= 12 ? (t->ac_flag & AGROUP ? 'P' : 'T') : '?'
+	,	(unsigned long)t->ac_pid
+	,	(unsigned long)(t->version >= 12 ? t->ac_tgid : 0)
+	,	(unsigned long)t->ac_uid
+	,	(unsigned long long)t->ac_etime
+	,	(unsigned long long)(t->version >= 12 ? t->ac_tgetime : 0)
+	,	(unsigned long long)(t->ac_utime+t->ac_stime)
+	,	(unsigned long long)t->hiwater_vm
+	,	(unsigned long long)t->hiwater_rss
+	,	(unsigned long)(t->version >= 12 ? MAJOR(t->ac_exe_dev) : 0)
+	,	(unsigned long)(t->version >= 12 ? MINOR(t->ac_exe_dev) : 0)
+	,	(unsigned long long)(t->version >= 12 ? t->ac_exe_inode : 0)
+	,	t->ac_comm
+	);
+}
+
+void handle_aggr(int mother, struct nlattr *na, int fd)
+{
+	int aggr_len = NLA_PAYLOAD(na->nla_len);
+	int len2 = 0;
+	pid_t rtid = 0;
+
+	na = (struct nlattr *) NLA_DATA(na);
+	while (len2 < aggr_len) {
+		switch (na->nla_type) {
+		case TASKSTATS_TYPE_PID:
+			rtid = *(int *) NLA_DATA(na);
+			PRINTF("PID\t%d\n", rtid);
+			break;
+		case TASKSTATS_TYPE_TGID:
+			rtid = *(int *) NLA_DATA(na);
+			PRINTF("TGID\t%d\n", rtid);
+			break;
+		case TASKSTATS_TYPE_STATS:
+			if (mother == TASKSTATS_TYPE_AGGR_PID)
+				print_procacct((struct taskstats *) NLA_DATA(na));
+			if (fd) {
+				if (write(fd, NLA_DATA(na), na->nla_len) < 0)
+					err(1, "write error\n");
+			}
+			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));
+	}
+}
+
+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;
+
+	int fd = 0;
+	int write_file = 0;
+	int maskset = 0;
+	char *logfile = NULL;
+	int containerset = 0;
+	char *containerpath = NULL;
+	int cfd = 0;
+	int forking = 0;
+	sigset_t sigset;
+
+	struct msgtemplate msg;
+
+	while (!forking) {
+		c = getopt(argc, argv, "m:vr:");
+		if (c < 0)
+			break;
+
+		switch (c) {
+		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;
+			break;
+		case 'v':
+			printf("debug on\n");
+			dbg = 1;
+			break;
+		default:
+			usage();
+			exit(-1);
+		}
+	}
+	if (!maskset) {
+		maskset = 1;
+		strncpy(cpumask, "1", sizeof(cpumask));
+		cpumask[sizeof(cpumask) - 1] = '\0';
+	}
+	printf("cpumask %s maskset %d\n", cpumask, maskset);
+
+	if (write_file) {
+		fd = open(logfile, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+		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;
+		}
+	}
+
+	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);
+			int mother = na->nla_type;
+
+			PRINTF("mother=%i\n", mother);
+			switch (na->nla_type) {
+			case TASKSTATS_TYPE_AGGR_PID:
+			case TASKSTATS_TYPE_AGGR_TGID:
+				/* For nested attributes, na follows */
+				handle_aggr(mother, na, fd);
+				break;
+			default:
+				fprintf(stderr, "Unexpected nla_type %d\n",
+					na->nla_type);
+			case TASKSTATS_TYPE_NULL:
+				break;
+			}
+			na = (struct nlattr *) (GENLMSG_DATA(&msg) + len);
+		}
+	} while (1);
+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;
+}