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authorKay Sievers <kay.sievers@suse.de>2005-06-05 04:53:17 +0200
committerKay Sievers <kay.sievers@suse.de>2005-06-05 04:53:17 +0200
commita15f42c46a7b9ceb5850ea4334c95f099ce74a6f (patch)
treeae59a9837b8a64d71b2d14f9640c00e2f5af8488 /udevd.c
parent1682c8c4a3909f9d80f17544bcfc6fb73379bc7e (diff)
udevd: improve timeout handling
Allow to override some parameters by environment keys. Signed-off-by: Kay Sievers <kay.sievers@suse.de>
Diffstat (limited to 'udevd.c')
-rw-r--r--udevd.c149
1 files changed, 96 insertions, 53 deletions
diff --git a/udevd.c b/udevd.c
index 371d715716..b5597eab40 100644
--- a/udevd.c
+++ b/udevd.c
@@ -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;