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udevd: improve timeout handling

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Allow to override some parameters by environment keys.

Signed-off-by: Kay Sievers <kay.sievers@suse.de>
This commit is contained in:
Kay Sievers 2005-06-05 04:53:17 +02:00
parent 1682c8c4a3
commit a15f42c46a
3 changed files with 107 additions and 62 deletions
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149
udevd.c
View File

@ -54,11 +54,10 @@ static int uevent_nl_sock;
static pid_t sid;
static int pipefds[2];
static long startup_time;
static unsigned long long expected_seqnum;
static volatile int sigchilds_waiting;
static volatile int run_msg_q;
static volatile int sig_flag;
static int init_phase = 1;
static int run_exec_q;
static int stop_exec_q;
@ -70,7 +69,13 @@ static void exec_queue_manager(void);
static void msg_queue_manager(void);
static void user_sighandler(void);
static void reap_sigchilds(void);
char *udev_bin;
static char *udev_bin;
static unsigned long long expected_seqnum;
static int event_timeout;
static int max_childs;
static int max_childs_running;
#ifdef USE_LOG
void log_message (int priority, const char *format, ...)
@ -115,6 +120,20 @@ static void msg_queue_insert(struct uevent_msg *msg)
return;
}
/* store timestamp of queuing */
sysinfo(&info);
msg->queue_time = info.uptime;
/* with the first event we provide a phase of shorter timeout */
if (init_phase) {
static long init_time;
if (init_time == 0)
init_time = info.uptime;
if (info.uptime - init_time >= UDEVD_INIT_TIME)
init_phase = 0;
}
/* don't delay messages with timeout set */
if (msg->timeout) {
dbg("move seq %llu with timeout %u to exec queue", msg->seqnum, msg->timeout);
@ -134,13 +153,8 @@ static void msg_queue_insert(struct uevent_msg *msg)
return;
}
}
/* store timestamp of queuing */
sysinfo(&info);
msg->queue_time = info.uptime;
list_add(&msg->node, &loop_msg->node);
dbg("queued message seq %llu", msg->seqnum);
info("seq %llu queued, devpath '%s'", msg->seqnum, msg->devpath);
/* run msg queue manager */
run_msg_q = 1;
@ -153,6 +167,7 @@ static void execute_udev(struct uevent_msg *msg)
{
char *const argv[] = { "udev", msg->subsystem, NULL };
pid_t pid;
struct sysinfo info;
pid = fork();
switch (pid) {
@ -174,7 +189,9 @@ static void execute_udev(struct uevent_msg *msg)
break;
default:
/* get SIGCHLD in main loop */
dbg("==> exec seq %llu [%d] working at '%s'", msg->seqnum, pid, msg->devpath);
sysinfo(&info);
info("seq %llu forked, pid %d, %ld seconds old",
msg->seqnum, pid, info.uptime - msg->queue_time);
msg->pid = pid;
}
}
@ -299,32 +316,43 @@ static int compare_devpath(const char *running, const char *waiting)
}
/* returns still running task for the same device, its parent or its physical device */
static struct uevent_msg *running_with_devpath(struct uevent_msg *msg)
static int running_with_devpath(struct uevent_msg *msg, int limit)
{
struct uevent_msg *loop_msg;
int childs_count = 0;
if (msg->devpath == NULL)
return NULL;
return 0;
/* skip any events with a timeout set */
if (msg->timeout)
return NULL;
if (msg->timeout != 0)
return 0;
list_for_each_entry(loop_msg, &running_list, node) {
if (limit && childs_count++ > limit) {
dbg("%llu, maximum number (%i) of child reached", msg->seqnum, childs_count);
return 1;
}
if (loop_msg->devpath == NULL)
continue;
/* return running parent/child device event */
if (compare_devpath(loop_msg->devpath, msg->devpath) != 0)
return loop_msg;
if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) {
dbg("%llu, child device event still running %llu (%s)",
msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
return 2;
}
/* return running physical device event */
if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0)
if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0)
return loop_msg;
if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0) {
dbg("%llu, physical device event still running %llu (%s)",
msg->seqnum, loop_msg->seqnum, loop_msg->devpath);
return 3;
}
}
return NULL;
return 0;
}
/* exec queue management routine executes the events and serializes events in the same sequence */
@ -332,36 +360,33 @@ static void exec_queue_manager(void)
{
struct uevent_msg *loop_msg;
struct uevent_msg *tmp_msg;
struct uevent_msg *msg;
int running;
running = running_processes();
dbg("%d processes runnning on system", running);
if (running < 0)
running = THROTTLE_MAX_RUNNING_CHILDS;
running = max_childs_running;
list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, node) {
/* check running processes in our session and possibly throttle */
if (running >= THROTTLE_MAX_RUNNING_CHILDS) {
running = running_processes_in_session(sid, THROTTLE_MAX_RUNNING_CHILDS+10);
dbg("%d processes running in session", running);
if (running >= THROTTLE_MAX_RUNNING_CHILDS) {
dbg("delay seq %llu, cause too many processes already running", loop_msg->seqnum);
if (running >= max_childs_running) {
running = running_processes_in_session(sid, max_childs_running+10);
dbg("at least %d processes running in session", running);
if (running >= max_childs_running) {
dbg("delay seq %llu, cause too many processes already running",
loop_msg->seqnum);
return;
}
}
msg = running_with_devpath(loop_msg);
if (!msg) {
if (running_with_devpath(loop_msg, max_childs) == 0) {
/* move event to run list */
list_move_tail(&loop_msg->node, &running_list);
execute_udev(loop_msg);
running++;
dbg("moved seq %llu to running list", loop_msg->seqnum);
} else {
dbg("delay seq %llu (%s), cause seq %llu (%s) is still running",
loop_msg->seqnum, loop_msg->devpath, msg->seqnum, msg->devpath);
}
} else
dbg("delay seq %llu (%s)", loop_msg->seqnum, loop_msg->devpath);
}
}
@ -381,11 +406,11 @@ static void msg_queue_manager(void)
struct uevent_msg *tmp_msg;
struct sysinfo info;
long msg_age = 0;
static int timeout = EVENT_INIT_TIMEOUT_SEC;
static int init = 1;
int timeout = event_timeout;
dbg("msg queue manager, next expected is %llu", expected_seqnum);
recheck:
sysinfo(&info);
list_for_each_entry_safe(loop_msg, tmp_msg, &msg_list, node) {
/* move event with expected sequence to the exec list */
if (loop_msg->seqnum == expected_seqnum) {
@ -393,15 +418,13 @@ recheck:
continue;
}
/* see if we are in the initialization phase and wait for the very first events */
if (init && (info.uptime - startup_time >= INIT_TIME_SEC)) {
init = 0;
timeout = EVENT_TIMEOUT_SEC;
dbg("initialization phase passed, set timeout to %i seconds", EVENT_TIMEOUT_SEC);
/* limit timeout during initialization phase */
if (init_phase) {
timeout = UDEVD_INIT_EVENT_TIMEOUT;
dbg("initialization phase, limit timeout to %i seconds", UDEVD_INIT_EVENT_TIMEOUT);
}
/* move event with expired timeout to the exec list */
sysinfo(&info);
msg_age = info.uptime - loop_msg->queue_time;
dbg("seq %llu is %li seconds old", loop_msg->seqnum, msg_age);
if (msg_age >= timeout) {
@ -629,10 +652,12 @@ static void udev_done(int pid)
{
/* find msg associated with pid and delete it */
struct uevent_msg *msg;
struct sysinfo info;
list_for_each_entry(msg, &running_list, node) {
if (msg->pid == pid) {
dbg("<== exec seq %llu came back", msg->seqnum);
sysinfo(&info);
info("seq %llu exit, %ld sec old", msg->seqnum, info.uptime - msg->queue_time);
run_queue_delete(msg);
/* we want to run the exec queue manager since there may
@ -734,13 +759,12 @@ static int init_uevent_nl_sock(void)
int main(int argc, char *argv[], char *envp[])
{
struct sysinfo info;
int maxsockplus;
int retval;
int fd;
struct sigaction act;
fd_set readfds;
const char *udevd_expected_seqnum;
const char *value;
int uevent_nl_active = 0;
logging_init("udevd");
@ -774,7 +798,6 @@ int main(int argc, char *argv[], char *envp[])
sid = setsid();
dbg("our session is %d", sid);
/* make sure we don't lock any path */
chdir("/");
umask(umask(077) | 022);
@ -840,23 +863,43 @@ int main(int argc, char *argv[], char *envp[])
goto exit;
}
/* possible override of udev binary, used for testing */
/* override of forked udev binary, used for testing */
udev_bin = getenv("UDEV_BIN");
if (udev_bin != NULL)
info("udev binary is set to '%s'", udev_bin);
else
udev_bin = UDEV_BIN;
/* possible init of expected_seqnum value */
udevd_expected_seqnum = getenv("UDEVD_EXPECTED_SEQNUM");
if (udevd_expected_seqnum != NULL) {
expected_seqnum = strtoull(udevd_expected_seqnum, NULL, 10);
/* init of expected_seqnum value */
value = getenv("UDEVD_EXPECTED_SEQNUM");
if (value) {
expected_seqnum = strtoull(value, NULL, 10);
info("initialize expected_seqnum to %llu", expected_seqnum);
}
/* get current time to provide shorter timeout on startup */
sysinfo(&info);
startup_time = info.uptime;
/* timeout to wait for missing events */
value = getenv("UDEVD_EVENT_TIMEOUT");
if (value)
event_timeout = strtoul(value, NULL, 10);
else
event_timeout = UDEVD_EVENT_TIMEOUT;
info("initialize event_timeout to %u", event_timeout);
/* maximum limit of forked childs */
value = getenv("UDEVD_MAX_CHILDS");
if (value)
max_childs = strtoul(value, NULL, 10);
else
max_childs = UDEVD_MAX_CHILDS;
info("initialize max_childs to %u", max_childs);
/* start to throttle forking if maximum number of _running_ childs is reached */
value = getenv("UDEVD_MAX_CHILDS_RUNNING");
if (value)
max_childs_running = strtoull(value, NULL, 10);
else
max_childs_running = UDEVD_MAX_CHILDS_RUNNING;
info("initialize max_childs_running to %u", max_childs_running);
FD_ZERO(&readfds);
FD_SET(udevd_sock, &readfds);
@ -893,7 +936,7 @@ int main(int argc, char *argv[], char *envp[])
msg = get_uevent_msg();
if (msg) {
msg_queue_insert(msg);
/* disable udevsend with first netlink message */
/* disable kernel uevent_helper with first netlink message */
if (!uevent_nl_active) {
info("uevent_nl message received, disable uevent_helper messages");
uevent_nl_active = 1;

14
udevd.h
View File

@ -26,21 +26,23 @@
#define UDEV_MAGIC "udevd_" UDEV_VERSION
#define UDEVD_SOCK_PATH "udevd"
#define SEND_WAIT_MAX_SECONDS 3
#define SEND_WAIT_LOOP_PER_SECOND 10
#define UDEVSEND_WAIT_MAX_SECONDS 3
#define UDEVSEND_WAIT_LOOP_PER_SECOND 10
#define UDEVD_PRIORITY -4
#define UDEV_PRIORITY -2
/* duration of initialization phase with shorter timeout */
#define INIT_TIME_SEC 5
#define EVENT_INIT_TIMEOUT_SEC 2
#define UDEVD_INIT_TIME 5
#define UDEVD_INIT_EVENT_TIMEOUT 2
/* timeout to wait for missing events */
#define EVENT_TIMEOUT_SEC 10
#define UDEVD_EVENT_TIMEOUT 5
/* maximum limit of runnig childs */
#define UDEVD_MAX_CHILDS 64
/* start to throttle forking if maximum number of running childs in our session is reached */
#define THROTTLE_MAX_RUNNING_CHILDS 10
#define UDEVD_MAX_CHILDS_RUNNING 8
/* environment buffer, should match the kernel's size in lib/kobject_uevent.h */
#define UEVENT_BUFFER_SIZE 1024

6
udevsend.c
View File

@ -185,7 +185,7 @@ int main(int argc, char *argv[], char *envp[])
dbg("usend_msg_len=%i", usend_msg_len);
/* If we can't send, try to start daemon and resend message */
loop = SEND_WAIT_MAX_SECONDS * SEND_WAIT_LOOP_PER_SECOND;
loop = UDEVSEND_WAIT_MAX_SECONDS * UDEVSEND_WAIT_LOOP_PER_SECOND;
while (--loop) {
retval = sendto(sock, &usend_msg, usend_msg_len, 0, (struct sockaddr *)&saddr, addrlen);
if (retval != -1) {
@ -208,8 +208,8 @@ int main(int argc, char *argv[], char *envp[])
dbg("udevd daemon started");
started_daemon = 1;
} else {
dbg("retry to connect %d", SEND_WAIT_MAX_SECONDS * SEND_WAIT_LOOP_PER_SECOND - loop);
usleep(1000 * 1000 / SEND_WAIT_LOOP_PER_SECOND);
dbg("retry to connect %d", UDEVSEND_WAIT_MAX_SECONDS * UDEVSEND_WAIT_LOOP_PER_SECOND - loop);
usleep(1000 * 1000 / UDEVSEND_WAIT_LOOP_PER_SECOND);
}
}