X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udevd.c;h=bd21f156146e7bc0162901f11d394a23c3948fad;hp=a8328bbb81a60d2a093089d6490ddb8f7e58577b;hb=f8a178a35b8dee2ee46a3de298345aa4faa8f41e;hpb=1e26698933e89c11dc6806d8bd37fd4386814239 diff --git a/udevd.c b/udevd.c index a8328bbb8..bd21f1561 100644 --- a/udevd.c +++ b/udevd.c @@ -28,11 +28,13 @@ #include #include #include +#include +#include +#include #include #include #include #include -#include #include #include @@ -45,6 +47,7 @@ /* global variables*/ static int udevsendsock; +static pid_t sid; static int pipefds[2]; static long startup_time; @@ -84,14 +87,14 @@ static void msg_dump_queue(void) #ifdef DEBUG struct hotplug_msg *msg; - list_for_each_entry(msg, &msg_list, list) + list_for_each_entry(msg, &msg_list, node) dbg("sequence %llu in queue", msg->seqnum); #endif } static void run_queue_delete(struct hotplug_msg *msg) { - list_del(&msg->list); + list_del(&msg->node); free(msg); } @@ -103,13 +106,13 @@ static void msg_queue_insert(struct hotplug_msg *msg) if (msg->seqnum == 0) { dbg("no SEQNUM, move straight to the exec queue"); - list_add(&msg->list, &exec_list); + list_add(&msg->node, &exec_list); run_exec_q = 1; return; } /* sort message by sequence number into list */ - list_for_each_entry_reverse(loop_msg, &msg_list, list) { + list_for_each_entry_reverse(loop_msg, &msg_list, node) { if (loop_msg->seqnum < msg->seqnum) break; @@ -123,7 +126,7 @@ static void msg_queue_insert(struct hotplug_msg *msg) sysinfo(&info); msg->queue_time = info.uptime; - list_add(&msg->list, &loop_msg->list); + list_add(&msg->node, &loop_msg->node); dbg("queued message seq %llu", msg->seqnum); /* run msg queue manager */ @@ -144,6 +147,8 @@ static void udev_run(struct hotplug_msg *msg) /* child */ close(udevsendsock); logging_close(); + + setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY); execve(udev_bin, argv, msg->envp); dbg("exec of child failed"); _exit(1); @@ -151,9 +156,6 @@ static void udev_run(struct hotplug_msg *msg) case -1: dbg("fork of child failed"); run_queue_delete(msg); - /* note: we never managed to run, so we had no impact on - * running_with_devpath(), so don't bother setting run_exec_q - */ break; default: /* get SIGCHLD in main loop */ @@ -162,6 +164,100 @@ static void udev_run(struct hotplug_msg *msg) } } +static int running_processes(void) +{ + int f; + static char buf[4096]; + int len; + int running; + const char *pos; + + f = open("/proc/stat", O_RDONLY); + if (f == -1) + return -1; + + len = read(f, buf, sizeof(buf)); + close(f); + + if (len <= 0) + return -1; + else + buf[len] = '\0'; + + pos = strstr(buf, "procs_running "); + if (pos == NULL) + return -1; + + if (sscanf(pos, "procs_running %u", &running) != 1) + return -1; + + return running; +} + +/* return the number of process es in our session, count only until limit */ +static int running_processes_in_session(pid_t session, int limit) +{ + DIR *dir; + struct dirent *dent; + int running = 0; + + dir = opendir("/proc"); + if (!dir) + return -1; + + /* read process info from /proc */ + for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) { + int f; + char procdir[64]; + char line[256]; + const char *pos; + char state; + pid_t ppid, pgrp, sess; + int len; + + if (!isdigit(dent->d_name[0])) + continue; + + snprintf(procdir, sizeof(procdir), "/proc/%s/stat", dent->d_name); + procdir[sizeof(procdir)-1] = '\0'; + + f = open(procdir, O_RDONLY); + if (f == -1) + continue; + + len = read(f, line, sizeof(line)); + close(f); + + if (len <= 0) + continue; + else + line[len] = '\0'; + + /* skip ugly program name */ + pos = strrchr(line, ')') + 2; + if (pos == NULL) + continue; + + if (sscanf(pos, "%c %d %d %d ", &state, &ppid, &pgrp, &sess) != 4) + continue; + + /* count only processes in our session */ + if (sess != session) + continue; + + /* count only running, no sleeping processes */ + if (state != 'R') + continue; + + running++; + if (limit > 0 && running >= limit) + break; + } + closedir(dir); + + return running; +} + static int compare_devpath(const char *running, const char *waiting) { int i; @@ -195,7 +291,7 @@ static struct hotplug_msg *running_with_devpath(struct hotplug_msg *msg) if (msg->devpath == NULL) return NULL; - list_for_each_entry(loop_msg, &running_list, list) { + list_for_each_entry(loop_msg, &running_list, node) { if (loop_msg->devpath == NULL) continue; @@ -218,13 +314,30 @@ static void exec_queue_manager(void) struct hotplug_msg *loop_msg; struct hotplug_msg *tmp_msg; struct hotplug_msg *msg; + int running; + + running = running_processes(); + dbg("%d processes runnning on system", running); + if (running < 0) + running = THROTTLE_MAX_RUNNING_CHILDS; + + 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); + return; + } + } - list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, list) { msg = running_with_devpath(loop_msg); if (!msg) { /* move event to run list */ - list_move_tail(&loop_msg->list, &running_list); + list_move_tail(&loop_msg->node, &running_list); udev_run(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", @@ -235,7 +348,7 @@ static void exec_queue_manager(void) static void msg_move_exec(struct hotplug_msg *msg) { - list_move_tail(&msg->list, &exec_list); + list_move_tail(&msg->node, &exec_list); run_exec_q = 1; expected_seqnum = msg->seqnum+1; dbg("moved seq %llu to exec, next expected is %llu", @@ -254,7 +367,7 @@ static void msg_queue_manager(void) dbg("msg queue manager, next expected is %llu", expected_seqnum); recheck: - list_for_each_entry_safe(loop_msg, tmp_msg, &msg_list, list) { + 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) { msg_move_exec(loop_msg); @@ -419,7 +532,7 @@ static void udev_done(int pid) /* find msg associated with pid and delete it */ struct hotplug_msg *msg; - list_for_each_entry(msg, &running_list, list) { + list_for_each_entry(msg, &running_list, node) { if (msg->pid == pid) { dbg("<== exec seq %llu came back", msg->seqnum); run_queue_delete(msg); @@ -529,10 +642,17 @@ int main(int argc, char *argv[], char *envp[]) } } + /* become session leader */ + sid = setsid(); + dbg("our session is %d", sid); + /* make sure we don't lock any path */ chdir("/"); umask(umask(077) | 022); + /*set a reasonable scheduling priority for the daemon */ + setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY); + /* Set fds to dev/null */ fd = open( "/dev/null", O_RDWR ); if (fd >= 0) { @@ -544,9 +664,6 @@ int main(int argc, char *argv[], char *envp[]) } else dbg("error opening /dev/null %s", strerror(errno)); - /* become session leader */ - setsid(); - /* setup signal handler pipe */ retval = pipe(pipefds); if (retval < 0) { @@ -573,6 +690,7 @@ int main(int argc, char *argv[], char *envp[]) dbg("error fcntl on write pipe: %s", strerror(errno)); /* set signal handlers */ + memset(&act, 0x00, sizeof(struct sigaction)); act.sa_handler = (void (*) (int))sig_handler; sigemptyset(&act.sa_mask); act.sa_flags = SA_RESTART; @@ -597,14 +715,14 @@ int main(int argc, char *argv[], char *envp[]) else udev_bin = UDEV_BIN; - /* possible set of expected_seqnum number */ + /* 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); dbg("initialize expected_seqnum to %llu", expected_seqnum); } - /* get current time to provide shorter startup timeout */ + /* get current time to provide shorter timeout on startup */ sysinfo(&info); startup_time = info.uptime;