chiark / gitweb /
udevd: improve timeout handling
authorKay Sievers <kay.sievers@suse.de>
Sun, 5 Jun 2005 02:53:17 +0000 (04:53 +0200)
committerKay Sievers <kay.sievers@suse.de>
Sun, 5 Jun 2005 02:53:17 +0000 (04:53 +0200)
Allow to override some parameters by environment keys.

Signed-off-by: Kay Sievers <kay.sievers@suse.de>
udevd.c
udevd.h
udevsend.c

diff --git a/udevd.c b/udevd.c
index 371d715..b5597ea 100644 (file)
--- 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;
diff --git a/udevd.h b/udevd.h
index b782d7a..60732fe 100644 (file)
--- a/udevd.h
+++ b/udevd.h
 
 #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
index 2b92e65..888a88d 100644 (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);
                }
        }