* [Patch 1/6] per task delay accounting taskstats interface: code cleanup
2006-07-11 4:23 [Patch 0/6] delay accounting & taskstats fixes Shailabh Nagar
@ 2006-07-11 4:27 ` Shailabh Nagar
2006-07-11 4:29 ` [Patch 2/6] per task delay accounting taskstats interface: documentation fix Shailabh Nagar
` (6 subsequent siblings)
7 siblings, 0 replies; 16+ messages in thread
From: Shailabh Nagar @ 2006-07-11 4:27 UTC (permalink / raw)
To: Andrew Morton
Cc: linux-kernel, Jay Lan, Chris Sturtivant, Paul Jackson,
Balbir Singh, Chandra Seetharaman
Cleanup cpumask related code and rearrange functions for clarity
Signed-Off-By: Shailabh Nagar <nagar@watson.ibm.com>
include/linux/taskstats_kern.h | 5 ---
kernel/taskstats.c | 53 ++++++++++++++++++++++-------------------
2 files changed, 29 insertions(+), 29 deletions(-)
Index: linux-2.6.18-rc1/include/linux/taskstats_kern.h
===================================================================
--- linux-2.6.18-rc1.orig/include/linux/taskstats_kern.h 2006-07-10 23:44:14.000000000 -0400
+++ linux-2.6.18-rc1/include/linux/taskstats_kern.h 2006-07-10 23:44:16.000000000 -0400
@@ -11,11 +11,6 @@
#include <linux/sched.h>
#include <net/genetlink.h>
-enum {
- TASKSTATS_MSG_UNICAST, /* send data only to requester */
- TASKSTATS_MSG_MULTICAST, /* send data to a group */
-};
-
#ifdef CONFIG_TASKSTATS
extern kmem_cache_t *taskstats_cache;
extern struct mutex taskstats_exit_mutex;
Index: linux-2.6.18-rc1/kernel/taskstats.c
===================================================================
--- linux-2.6.18-rc1.orig/kernel/taskstats.c 2006-07-10 23:44:14.000000000 -0400
+++ linux-2.6.18-rc1/kernel/taskstats.c 2006-07-10 23:44:16.000000000 -0400
@@ -99,35 +99,45 @@ static int prepare_reply(struct genl_inf
return 0;
}
-static int send_reply(struct sk_buff *skb, pid_t pid, int event, unsigned int cpu)
+/*
+ * Send taskstats data in @skb to listener with nl_pid @pid
+ */
+static int send_reply(struct sk_buff *skb, pid_t pid)
{
struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data);
- struct listener_list *listeners;
- struct list_head *p, *tmp;
- void *reply;
+ void *reply = genlmsg_data(genlhdr);
int rc;
- reply = genlmsg_data(genlhdr);
-
rc = genlmsg_end(skb, reply);
if (rc < 0) {
nlmsg_free(skb);
return rc;
}
- if (event == TASKSTATS_MSG_UNICAST)
- return genlmsg_unicast(skb, pid);
+ return genlmsg_unicast(skb, pid);
+}
- /*
- * Taskstats multicast is unicasts to listeners who have registered
- * interest in cpu
- */
+/*
+ * Send taskstats data in @skb to listeners registered for @cpu's exit data
+ */
+static int send_cpu_listeners(struct sk_buff *skb, unsigned int cpu)
+{
+ struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data);
+ struct listener_list *listeners;
+ struct listener *s, *tmp;
+ void *reply = genlmsg_data(genlhdr);
+ int rc, ret;
+
+ rc = genlmsg_end(skb, reply);
+ if (rc < 0) {
+ nlmsg_free(skb);
+ return rc;
+ }
+ rc = 0;
listeners = &per_cpu(listener_array, cpu);
down_write(&listeners->sem);
- list_for_each_safe(p, tmp, &listeners->list) {
- int ret;
- struct listener *s = list_entry(p, struct listener, list);
+ list_for_each_entry_safe(s, tmp, &listeners->list, list) {
ret = genlmsg_unicast(skb, s->pid);
if (ret) {
list_del(&s->list);
@@ -253,11 +263,10 @@ ret:
static int add_del_listener(pid_t pid, cpumask_t *maskp, int isadd)
{
- struct listener *s;
struct listener_list *listeners;
+ struct listener *s, *tmp;
unsigned int cpu;
cpumask_t mask = *maskp;
- struct list_head *p;
if (!cpus_subset(mask, cpu_possible_map))
return -EINVAL;
@@ -282,12 +291,9 @@ static int add_del_listener(pid_t pid, c
/* Deregister or cleanup */
cleanup:
for_each_cpu_mask(cpu, mask) {
- struct list_head *tmp;
-
listeners = &per_cpu(listener_array, cpu);
down_write(&listeners->sem);
- list_for_each_safe(p, tmp, &listeners->list) {
- s = list_entry(p, struct listener, list);
+ list_for_each_entry_safe(s, tmp, &listeners->list, list) {
if (s->pid == pid) {
list_del(&s->list);
kfree(s);
@@ -376,8 +382,7 @@ static int taskstats_user_cmd(struct sk_
nla_nest_end(rep_skb, na);
- return send_reply(rep_skb, info->snd_pid, TASKSTATS_MSG_UNICAST,
- CPU_DONT_CARE);
+ return send_reply(rep_skb, info->snd_pid);
nla_put_failure:
return genlmsg_cancel(rep_skb, reply);
@@ -475,7 +480,7 @@ void taskstats_exit_send(struct task_str
nla_nest_end(rep_skb, na);
send:
- send_reply(rep_skb, 0, TASKSTATS_MSG_MULTICAST, mycpu);
+ send_cpu_listeners(rep_skb, mycpu);
return;
nla_put_failure:
^ permalink raw reply [flat|nested] 16+ messages in thread* [Patch 2/6] per task delay accounting taskstats interface: documentation fix
2006-07-11 4:23 [Patch 0/6] delay accounting & taskstats fixes Shailabh Nagar
2006-07-11 4:27 ` [Patch 1/6] per task delay accounting taskstats interface: code cleanup Shailabh Nagar
@ 2006-07-11 4:29 ` Shailabh Nagar
2006-07-11 4:30 ` [Patch 3/6] per task delay accounting taskstats interface: fix early sem init Shailabh Nagar
` (5 subsequent siblings)
7 siblings, 0 replies; 16+ messages in thread
From: Shailabh Nagar @ 2006-07-11 4:29 UTC (permalink / raw)
To: Andrew Morton
Cc: linux-kernel, Jay Lan, Chris Sturtivant, Paul Jackson,
Balbir Singh, Chandra Seetharaman
Change documentation and example program to reflect the flow control
issues being addressed by the cpumask changes.
Signed-Off-By: Shailabh Nagar <nagar@watson.ibm.com>
Documentation/accounting/getdelays.c | 612 +++++++++++++++++----------------
Documentation/accounting/taskstats.txt | 64 ++-
2 files changed, 368 insertions(+), 308 deletions(-)
Index: linux-2.6.18-rc1/Documentation/accounting/taskstats.txt
===================================================================
--- linux-2.6.18-rc1.orig/Documentation/accounting/taskstats.txt 2006-07-10 23:44:10.000000000 -0400
+++ linux-2.6.18-rc1/Documentation/accounting/taskstats.txt 2006-07-10 23:44:18.000000000 -0400
@@ -26,20 +26,28 @@ leader - a process is deemed alive as lo
Usage
-----
-To get statistics during task's lifetime, userspace opens a unicast netlink
+To get statistics during a task's lifetime, userspace opens a unicast netlink
socket (NETLINK_GENERIC family) and sends commands specifying a pid or a tgid.
The response contains statistics for a task (if pid is specified) or the sum of
statistics for all tasks of the process (if tgid is specified).
-To obtain statistics for tasks which are exiting, userspace opens a multicast
-netlink socket. Each time a task exits, its per-pid statistics is always sent
-by the kernel to each listener on the multicast socket. In addition, if it is
-the last thread exiting its thread group, an additional record containing the
-per-tgid stats are also sent. The latter contains the sum of per-pid stats for
-all threads in the thread group, both past and present.
+To obtain statistics for tasks which are exiting, the userspace listener
+sends a register command and specifies a cpumask. Whenever a task exits on
+one of the cpus in the cpumask, its per-pid statistics are sent to the
+registered listener. Using cpumasks allows the data received by one listener
+to be limited and assists in flow control over the netlink interface and is
+explained in more detail below.
+
+If the exiting task is the last thread exiting its thread group,
+an additional record containing the per-tgid stats is also sent to userspace.
+The latter contains the sum of per-pid stats for all threads in the thread
+group, both past and present.
getdelays.c is a simple utility demonstrating usage of the taskstats interface
-for reporting delay accounting statistics.
+for reporting delay accounting statistics. Users can register cpumasks,
+send commands and process responses, listen for per-tid/tgid exit data,
+write the data received to a file and do basic flow control by increasing
+receive buffer sizes.
Interface
---------
@@ -66,10 +74,20 @@ The messages are in the format
The taskstats payload is one of the following three kinds:
-1. Commands: Sent from user to kernel. The payload is one attribute, of type
-TASKSTATS_CMD_ATTR_PID/TGID, containing a u32 pid or tgid in the attribute
-payload. The pid/tgid denotes the task/process for which userspace wants
-statistics.
+1. Commands: Sent from user to kernel. Commands to get data on
+a pid/tgid consist of one attribute, of type TASKSTATS_CMD_ATTR_PID/TGID,
+containing a u32 pid or tgid in the attribute payload. The pid/tgid denotes
+the task/process for which userspace wants statistics.
+
+Commands to register/deregister interest in exit data from a set of cpus
+consist of one attribute, of type
+TASKSTATS_CMD_ATTR_REGISTER/DEREGISTER_CPUMASK and contain a cpumask in the
+attribute payload. The cpumask is specified as an ascii string of
+comma-separated cpu ranges e.g. to listen to exit data from cpus 1,2,3,5,7,8
+the cpumask would be "1-3,5,7-8". If userspace forgets to deregister interest
+in cpus before closing the listening socket, the kernel cleans up its interest
+set over time. However, for the sake of efficiency, an explicit deregistration
+is advisable.
2. Response for a command: sent from the kernel in response to a userspace
command. The payload is a series of three attributes of type:
@@ -138,4 +156,26 @@ struct too much, requiring disparate use
unnecessarily receive large structures whose fields are of no interest, then
extending the attributes structure would be worthwhile.
+Flow control for taskstats
+--------------------------
+
+When the rate of task exits becomes large, a listener may not be able to keep
+up with the kernel's rate of sending per-tid/tgid exit data leading to data
+loss. This possibility gets compounded when the taskstats structure gets
+extended and the number of cpus grows large.
+
+To avoid losing statistics, userspace should do one or more of the following:
+
+- increase the receive buffer sizes for the netlink sockets opened by
+listeners to receive exit data.
+
+- create more listeners and reduce the number of cpus being listened to by
+each listener. In the extreme case, there could be one listener for each cpu.
+Users may also consider setting the cpu affinity of the listener to the subset
+of cpus to which it listens, especially if they are listening to just one cpu.
+
+Despite these measures, if the userspace receives ENOBUFS error messages
+indicated overflow of receive buffers, it should take measures to handle the
+loss of data.
+
----
Index: linux-2.6.18-rc1/Documentation/accounting/getdelays.c
===================================================================
--- linux-2.6.18-rc1.orig/Documentation/accounting/getdelays.c 2006-07-10 23:44:10.000000000 -0400
+++ linux-2.6.18-rc1/Documentation/accounting/getdelays.c 2006-07-10 23:44:18.000000000 -0400
@@ -5,6 +5,7 @@
*
* Copyright (C) Shailabh Nagar, IBM Corp. 2005
* Copyright (C) Balbir Singh, IBM Corp. 2006
+ * Copyright (c) Jay Lan, SGI. 2006
*
*/
@@ -36,341 +37,360 @@
#define err(code, fmt, arg...) do { printf(fmt, ##arg); exit(code); } while (0)
int done = 0;
+int rcvbufsz=0;
+
+ char name[100];
+int dbg=0, print_delays=0;
+__u64 stime, utime;
+#define PRINTF(fmt, arg...) { \
+ if (dbg) { \
+ printf(fmt, ##arg); \
+ } \
+ }
+
+/* Maximum size of response requested or message sent */
+#define MAX_MSG_SIZE 256
+/* Maximum number of cpus expected to be specified in a cpumask */
+#define MAX_CPUS 32
+/* Maximum length of pathname to log file */
+#define MAX_FILENAME 256
+
+struct msgtemplate {
+ struct nlmsghdr n;
+ struct genlmsghdr g;
+ char buf[MAX_MSG_SIZE];
+};
+
+char cpumask[100+6*MAX_CPUS];
/*
* Create a raw netlink socket and bind
*/
-static int create_nl_socket(int protocol, int groups)
+static int create_nl_socket(int protocol)
{
- socklen_t addr_len;
- int fd;
- struct sockaddr_nl local;
+ int fd;
+ struct sockaddr_nl local;
- fd = socket(AF_NETLINK, SOCK_RAW, protocol);
- if (fd < 0)
- return -1;
+ 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) {
+ printf("Unable to set socket rcv buf size to %d\n",
+ rcvbufsz);
+ 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;
-}
+ memset(&local, 0, sizeof(local));
+ local.nl_family = AF_NETLINK;
-int sendto_fd(int s, const char *buf, int bufLen)
-{
- struct sockaddr_nl nladdr;
- int r;
+ if (bind(fd, (struct sockaddr *) &local, sizeof(local)) < 0)
+ goto error;
+
+ return fd;
+error:
+ close(fd);
+ return -1;
+}
- 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;
+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
*/
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;
-}
+ struct {
+ struct nlmsghdr n;
+ struct genlmsghdr g;
+ char buf[256];
+ } ans;
+
+ int id, 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);
+
+ 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;
-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);
+ 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 sigchld(int sig)
+void print_delayacct(struct taskstats *t)
{
- done = 1;
+ 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);
}
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 c, rc, rep_len, aggr_len, len2, cmd_type;
+ __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[128];
+ int loop = 0;
+
+ struct msgtemplate msg;
+
+ while (1) {
+ c = getopt(argc, argv, "dw:r:m:t:p:v:l");
+ if (c < 0)
+ break;
- 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);
+ switch (c) {
+ case 'd':
+ printf("print delayacct stats ON\n");
+ print_delays = 1;
+ break;
+ case 'w':
+ strncpy(logfile, optarg, MAX_FILENAME);
+ 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;
+ print_delays = 1;
+ break;
+ case 'p':
+ tid = atoi(optarg);
+ if (!tid)
+ err(1, "Invalid pid\n");
+ cmd_type = TASKSTATS_CMD_ATTR_PID;
+ print_delays = 1;
+ break;
+ case 'v':
+ printf("debug on\n");
+ dbg = 1;
+ break;
+ case 'l':
+ printf("listen forever\n");
+ loop = 1;
+ break;
+ default:
+ printf("Unknown option %d\n", c);
+ 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;
+
+ 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);
+ }
}
- rep_len = recv(nl_sd, &ans, sizeof(ans), 0);
- nladdr.nl_family = AF_NETLINK;
- nladdr.nl_groups = TASKSTATS_LISTEN_GROUP;
+ if ((nl_sd = create_nl_socket(NETLINK_GENERIC)) < 0)
+ err(1, "error creating Netlink socket\n");
- if (ans.n.nlmsg_type == NLMSG_ERROR) { /* error */
- printf("error received NACK - leaving\n");
- exit(1);
+
+ mypid = getpid();
+ id = get_family_id(nl_sd);
+ if (!id) {
+ printf("Error getting family id, errno %d", errno);
+ goto err;
}
+ PRINTF("family id %d\n", id);
- if (rep_len < 0) {
- err(1, "error receiving reply message via Netlink\n");
- break;
+ if (maskset) {
+ rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
+ TASKSTATS_CMD_ATTR_REGISTER_CPUMASK,
+ &cpumask, sizeof(cpumask));
+ PRINTF("Sent register cpumask, retval %d\n", rc);
+ if (rc < 0) {
+ printf("error sending register cpumask\n");
+ goto err;
+ }
}
- /* Validate response message */
- if (!NLMSG_OK((&ans.n), rep_len))
- err(1, "invalid reply message received via Netlink\n");
+ 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) {
+ printf("error sending tid/tgid cmd\n");
+ goto done;
+ }
+ }
- rep_len = GENLMSG_PAYLOAD(&ans.n);
+ do {
+ int i;
- 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;
+ rep_len = recv(nl_sd, &msg, sizeof(msg), 0);
+ PRINTF("received %d bytes\n", rep_len);
+
+ if (rep_len < 0) {
+ printf("nonfatal reply error: errno %d\n", errno);
+ continue;
+ }
+ if (msg.n.nlmsg_type == NLMSG_ERROR ||
+ !NLMSG_OK((&msg.n), rep_len)) {
+ printf("fatal reply error, errno %d\n", errno);
+ goto done;
+ }
+
+ PRINTF("nlmsghdr size=%d, 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;
+ i = 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 (fd) {
+ if (write(fd, NLA_DATA(na), na->nla_len) < 0) {
+ err(1,"write error\n");
+ }
+ }
+ if (!loop)
+ goto done;
+ break;
+ default:
+ printf("Unknown nested nla_type %d\n", na->nla_type);
+ break;
+ }
+ len2 += NLA_ALIGN(na->nla_len);
+ na = (struct nlattr *) ((char *) na + len2);
+ }
+ break;
+
+ default:
+ printf("Unknown nla_type %d\n", na->nla_type);
+ break;
}
- break;
- }
- len2 += NLA_ALIGN(na->nla_len);
- na = (struct nlattr *) ((char *) na + len2);
- if (done)
- break;
+ na = (struct nlattr *) (GENLMSG_DATA(&msg) + len);
}
- }
- na = (struct nlattr *) (GENLMSG_DATA(&ans) + len);
- if (done)
- break;
+ } while (loop);
+done:
+ if (maskset) {
+ rc = send_cmd(nl_sd, id, mypid, TASKSTATS_CMD_GET,
+ TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK,
+ &cpumask, sizeof(cpumask));
+ printf("Sent deregister mask, retval %d\n", rc);
+ if (rc < 0)
+ err(rc, "error sending deregister cpumask\n");
}
- if (done)
- break;
- }
- while (1);
-
- close(nl_sd);
- return 0;
+err:
+ close(nl_sd);
+ if (fd)
+ close(fd);
+ return 0;
}
^ permalink raw reply [flat|nested] 16+ messages in thread* Re: [Patch 0/6] delay accounting & taskstats fixes
2006-07-11 4:23 [Patch 0/6] delay accounting & taskstats fixes Shailabh Nagar
` (5 preceding siblings ...)
2006-07-11 4:36 ` [Patch 6/6] per task delay accounting taskstats interface: fix clone skbs for each listener Shailabh Nagar
@ 2006-07-11 4:50 ` Shailabh Nagar
2006-07-11 11:28 ` Christoph Hellwig
7 siblings, 0 replies; 16+ messages in thread
From: Shailabh Nagar @ 2006-07-11 4:50 UTC (permalink / raw)
To: Andrew Morton
Cc: linux-kernel, Jay Lan, Chris Sturtivant, Paul Jackson,
Balbir Singh, Chandra Seetharaman
On Tue, 2006-07-11 at 00:23, Shailabh Nagar wrote:
> Some results showing the cpumask feature
> works as expected will follow separately.
To illustrate the basic premise behind the cpumask changes
namely, reducing the number of cpus results in fewer overflow
conditions, Chandra ran the following experiment on an
8-way PIII box:
- "mkthreads 1000 1000" (the program which only forks/exits) with
minimum time spent inside the thread function. This is basically an exit
rate that is higher than the 1000/cpu/sec discussed earlier.
- A slightly modified version of the getdelays.c example that is
included in patch 2/6 in this series of postings. Modification was
to print only the number of receives and number of ENOBUFS seen.
The -m parameter specifies the cpumask,
-r parameter is the size of the socket receive buffer
-l results in listening for exit data
The following sets of runs are self-explanatory.
Initial run emulates the earlier behaviour where one listener
receives data for all cpus. As the number of cpus to which it
listens is reduced, the ENOBUFS reduce.
Similarly, increasing the receive buffer size also cuts down
on the ENOBUFS, further helped by reducing number of cpus listened
to. The final data point, not shown here, is when the receive
buffer size is set to some high number like 8K when the ENOBUFS aren't
seen at all.
===================================
Each output shows
stats <number of msgs rcvd> enobufs <num of enobufs seen>
cumulatively
elm3b94:/tmp # ./getdelays -m 0-7 -r 512 -l
cpumask 0-7 maskset 1
receive buf size 512
listen forever
stats 100000, enobufs 2540
stats 200000, enobufs 5701
stats 300000, enobufs 8482
stats 400000, enobufs 11332
stats 500000, enobufs 14256
stats 600000, enobufs 17150
stats 700000, enobufs 19981
stats 800000, enobufs 22971
stats 900000, enobufs 26324
stats 1000000, enobufs 29291
elm3b94:/tmp # ./getdelays -m 0-3 -r 512 -l
cpumask 0-3 maskset 1
receive buf size 512
listen forever
stats 100000, enobufs 831
stats 200000, enobufs 1772
stats 300000, enobufs 2728
stats 400000, enobufs 3820
stats 500000, enobufs 5030
stats 600000, enobufs 6501
stats 700000, enobufs 7885
stats 800000, enobufs 8971
stats 900000, enobufs 10262
stats 1000000, enobufs 11786
elm3b94:/tmp # ./getdelays -m 2-3 -r 512 -l
cpumask 2-3 maskset 1
receive buf size 512
listen forever
stats 100000, enobufs 106
stats 200000, enobufs 206
stats 300000, enobufs 313
stats 400000, enobufs 389
stats 500000, enobufs 477
stats 600000, enobufs 676
stats 700000, enobufs 860
stats 800000, enobufs 1048
stats 900000, enobufs 1189
stats 1000000, enobufs 1303
elm3b94:/tmp # ./getdelays -m 0 -r 512 -l
cpumask 0 maskset 1
receive buf size 512
listen forever
stats 100000, enobufs 100
stats 200000, enobufs 162
stats 300000, enobufs 302
stats 400000, enobufs 399
stats 500000, enobufs 507
stats 600000, enobufs 571
stats 700000, enobufs 666
stats 800000, enobufs 725
stats 900000, enobufs 821
stats 1000000, enobufs 909
================= with recv buf size 2048
elm3b94:/tmp # ./getdelays -m 0-7 -r 2048 -l
cpumask 0-7 maskset 1
receive buf size 2048
listen forever
stats 100000, enobufs 35
stats 200000, enobufs 88
stats 300000, enobufs 123
stats 400000, enobufs 138
stats 500000, enobufs 155
stats 600000, enobufs 191
stats 700000, enobufs 223
stats 800000, enobufs 238
stats 900000, enobufs 280
stats 1000000, enobufs 319
elm3b94:/tmp # ./getdelays -m 4-7 -r 2048 -l
cpumask 4-7 maskset 1
receive buf size 2048
listen forever
stats 100000, enobufs 10
stats 200000, enobufs 17
stats 300000, enobufs 28
stats 400000, enobufs 35
stats 500000, enobufs 49
stats 600000, enobufs 63
stats 700000, enobufs 80
stats 800000, enobufs 94
stats 900000, enobufs 114
stats 1000000, enobufs 138
elm3b94:/tmp # ./getdelays -m 2-3 -r 2048 -l
cpumask 2-3 maskset 1
receive buf size 2048
listen forever
stats 100000, enobufs 5
stats 200000, enobufs 6
stats 300000, enobufs 10
stats 400000, enobufs 14
stats 500000, enobufs 19
stats 600000, enobufs 33
stats 700000, enobufs 38
stats 800000, enobufs 43
stats 900000, enobufs 54
stats 1000000, enobufs 59
elm3b94:/tmp # ./getdelays -m 1 -r 2048 -l
cpumask 1 maskset 1
receive buf size 2048
listen forever
stats 100000, enobufs 3
stats 200000, enobufs 6
stats 300000, enobufs 19
stats 400000, enobufs 25
stats 500000, enobufs 30
stats 600000, enobufs 31
stats 700000, enobufs 33
stats 800000, enobufs 45
stats 900000, enobufs 48
stats 1000000, enobufs 52
^ permalink raw reply [flat|nested] 16+ messages in thread