From: Kay Sievers Date: Wed, 29 Oct 2008 16:32:13 +0000 (+0100) Subject: udevd: merge exec and run queue to minimize devpath string compares X-Git-Tag: 174~1367 X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=0bc74ea79f68a89c5ec4bf5676dede97626ceade;ds=sidebyside udevd: merge exec and run queue to minimize devpath string compares --- diff --git a/udev/udev-event.c b/udev/udev-event.c index 02c5c99dc..79a4cde65 100644 --- a/udev/udev-event.c +++ b/udev/udev-event.c @@ -706,6 +706,11 @@ int udev_event_execute_run(struct udev_event *event) util_strlcpy(program, cmd, sizeof(program)); udev_event_apply_format(event, program, sizeof(program)); + if (event->trace) + printf("run %s (%llu) '%s'\n", + udev_device_get_syspath(event->dev), + udev_device_get_seqnum(event->dev), + program); envp = udev_device_get_properties_envp(event->dev); if (util_run_program(event->udev, program, envp, NULL, 0, NULL) != 0) { if (!udev_list_entry_get_flag(list_entry)) diff --git a/udev/udev.h b/udev/udev.h index faa1bf685..732b13139 100644 --- a/udev/udev.h +++ b/udev/udev.h @@ -71,6 +71,7 @@ struct udev_event { pid_t pid; int exitstatus; time_t queue_time; + unsigned long long int delaying_seqnum; unsigned int group_final:1; unsigned int owner_final:1; unsigned int mode_final:1; @@ -78,6 +79,7 @@ struct udev_event { unsigned int devlink_final:1; unsigned int run_final:1; unsigned int ignore_device:1; + unsigned int trace:1; unsigned int test:1; }; diff --git a/udev/udevd.c b/udev/udevd.c index 0bacb3994..6f2e188ce 100644 --- a/udev/udevd.c +++ b/udev/udevd.c @@ -62,7 +62,6 @@ static struct udev_rules *rules; static struct udev_ctrl *udev_ctrl; static struct udev_monitor *kernel_monitor; static int inotify_fd = -1; - static int signal_pipe[2] = {-1, -1}; static volatile int sigchilds_waiting; static volatile int udev_exit; @@ -70,9 +69,8 @@ static volatile int reload_config; static int run_exec_q; static int stop_exec_q; static int max_childs; - -static struct udev_list_node exec_list; -static struct udev_list_node running_list; +static int childs; +static struct udev_list_node event_list; enum event_state { EVENT_QUEUED, @@ -137,7 +135,7 @@ static void export_event_state(struct udev_event *event, enum event_state state) unlink(filename); /* clean up possibly empty queue directory */ - if (udev_list_is_empty(&exec_list) && udev_list_is_empty(&running_list)) + if (udev_list_is_empty(&event_list)) util_delete_path(event->udev, filename); break; case EVENT_FAILED: @@ -146,7 +144,7 @@ static void export_event_state(struct udev_event *event, enum event_state state) rename(filename, filename_failed); /* clean up possibly empty queue directory */ - if (udev_list_is_empty(&exec_list) && udev_list_is_empty(&running_list)) + if (udev_list_is_empty(&event_list)) util_delete_path(event->udev, filename); break; } @@ -180,6 +178,13 @@ static void event_fork(struct udev_event *event) struct sigaction act; int err; + if (debug_trace) { + event->trace = 1; + printf("fork %s (%llu)\n", + udev_device_get_syspath(event->dev), + udev_device_get_seqnum(event->dev)); + } + pid = fork(); switch (pid) { case 0: @@ -221,6 +226,7 @@ static void event_fork(struct udev_event *event) /* execute RUN= */ if (err == 0 && !event->ignore_device && udev_get_run(event->udev)) udev_event_execute_run(event); + info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err); logging_close(); if (err != 0) @@ -239,6 +245,7 @@ static void event_fork(struct udev_event *event) udev_device_get_subsystem(event->dev), time(NULL) - event->queue_time); event->pid = pid; + childs++; } } @@ -265,24 +272,15 @@ static void event_queue_insert(struct udev_event *event) close(fd); } - /* run one event after the other in debug mode */ - if (debug_trace) { - udev_list_node_append(&event->node, &running_list); - event_fork(event); - waitpid(event->pid, NULL, 0); - event_queue_delete(event); - return; - } + + udev_list_node_append(&event->node, &event_list); + run_exec_q = 1; /* run all events with a timeout set immediately */ if (udev_device_get_timeout(event->dev) > 0) { - udev_list_node_append(&event->node, &running_list); event_fork(event); return; } - - udev_list_node_append(&event->node, &exec_list); - run_exec_q = 1; } static int mem_size_mb(void) @@ -312,7 +310,7 @@ static int compare_devpath(const char *running, const char *waiting) { int i = 0; - while (running[i] == waiting[i] && running[i] != '\0') + while (running[i] != '\0' && running[i] == waiting[i]) i++; /* identical device event found */ @@ -332,23 +330,34 @@ static int compare_devpath(const char *running, const char *waiting) } /* lookup event for identical, parent, child, or physical device */ -static int devpath_busy(struct udev_event *event, int limit) +static int devpath_busy(struct udev_event *event) { struct udev_list_node *loop; - int childs_count = 0; - /* check exec-queue which may still contain delayed events we depend on */ - udev_list_node_foreach(loop, &exec_list) { + if (event->delaying_seqnum > 0) { + } + /* check if queue contains events we depend on */ + udev_list_node_foreach(loop, &event_list) { struct udev_event *loop_event = node_to_event(loop); - /* skip ourself and all later events */ + /* we already found a later event, earlier can not block us, no need to check again */ + if (udev_device_get_seqnum(loop_event->dev) < event->delaying_seqnum) + continue; + + /* event we checked earlier still exists, no need to check again */ + if (udev_device_get_seqnum(loop_event->dev) == event->delaying_seqnum) + return 2; + + /* found ourself, no later event can block us */ if (udev_device_get_seqnum(loop_event->dev) >= udev_device_get_seqnum(event->dev)) break; /* check our old name */ if (udev_device_get_devpath_old(event->dev) != NULL) - if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0) - return 2; + if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0) { + event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev); + return 3; + } /* check identical, parent, or child device event */ if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) { @@ -356,57 +365,10 @@ static int devpath_busy(struct udev_event *event, int limit) udev_device_get_seqnum(event->dev), udev_device_get_seqnum(loop_event->dev), udev_device_get_devpath(loop_event->dev)); - return 3; - } - - /* check for our major:minor number */ - if (major(udev_device_get_devnum(event->dev)) > 0 && - udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) && - strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) { - dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n", - udev_device_get_seqnum(event->dev), - udev_device_get_seqnum(loop_event->dev), - major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev))); + event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev); return 4; } - /* check physical device event (special case of parent) */ - if (udev_device_get_physdevpath(event->dev) != NULL && - strcmp(udev_device_get_action(event->dev), "add") == 0) - if (compare_devpath(udev_device_get_devpath(loop_event->dev), - udev_device_get_physdevpath(event->dev)) != 0) { - dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n", - udev_device_get_seqnum(event->dev), - udev_device_get_seqnum(loop_event->dev), - udev_device_get_devpath(loop_event->dev)); - return 5; - } - } - - /* check run queue for still running events */ - udev_list_node_foreach(loop, &running_list) { - struct udev_event *loop_event = node_to_event(loop); - - if (childs_count++ >= limit) { - info(event->udev, "%llu, maximum number (%i) of childs reached\n", - udev_device_get_seqnum(event->dev), childs_count); - return 1; - } - - /* check our old name */ - if (udev_device_get_devpath_old(event->dev) != NULL) - if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0) - return 2; - - /* check identical, parent, or child device event */ - if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) { - dbg(event->udev, "%llu, device event still running %llu (%s)\n", - udev_device_get_seqnum(event->dev), - udev_device_get_seqnum(loop_event->dev), - udev_device_get_devpath(loop_event->dev)); - return 3; - } - /* check for our major:minor number */ if (major(udev_device_get_devnum(event->dev)) > 0 && udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) && @@ -415,7 +377,8 @@ static int devpath_busy(struct udev_event *event, int limit) udev_device_get_seqnum(event->dev), udev_device_get_seqnum(loop_event->dev), major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev))); - return 4; + event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev); + return 5; } /* check physical device event (special case of parent) */ @@ -427,7 +390,8 @@ static int devpath_busy(struct udev_event *event, int limit) udev_device_get_seqnum(event->dev), udev_device_get_seqnum(loop_event->dev), udev_device_get_devpath(loop_event->dev)); - return 5; + event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev); + return 6; } } return 0; @@ -439,23 +403,34 @@ static void event_queue_manager(struct udev *udev) struct udev_list_node *loop; struct udev_list_node *tmp; - if (udev_list_is_empty(&exec_list)) + if (udev_list_is_empty(&event_list)) { + if (childs > 0) { + err(udev, "event list empty, but childs count is %i", childs); + childs = 0; + } return; + } - udev_list_node_foreach_safe(loop, tmp, &exec_list) { + udev_list_node_foreach_safe(loop, tmp, &event_list) { struct udev_event *loop_event = node_to_event(loop); - /* serialize and wait for parent or child events */ - if (devpath_busy(loop_event, max_childs) != 0) { + if (childs >= max_childs) { + info(udev, "maximum number (%i) of childs reached\n", childs); + break; + } + + if (loop_event->pid != 0) + continue; + + /* do not start event if parent or child event is still running */ + if (devpath_busy(loop_event) != 0) { dbg(udev, "delay seq %llu (%s)\n", udev_device_get_seqnum(loop_event->dev), udev_device_get_devpath(loop_event->dev)); continue; } - /* move event to run list */ - udev_list_node_remove(&loop_event->node); - udev_list_node_append(&loop_event->node, &running_list); + /* do dendencies, start event */ event_fork(loop_event); dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev)); } @@ -526,7 +501,6 @@ static void handle_ctrl_msg(struct udev_ctrl *uctrl) info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i); max_childs = i; } - udev_ctrl_msg_unref(ctrl_msg); } @@ -555,7 +529,7 @@ static void udev_done(int pid, int exitstatus) struct udev_list_node *loop; /* find event associated with pid and delete it */ - udev_list_node_foreach(loop, &running_list) { + udev_list_node_foreach(loop, &event_list) { struct udev_event *loop_event = node_to_event(loop); if (loop_event->pid == pid) { @@ -563,9 +537,14 @@ static void udev_done(int pid, int exitstatus) udev_device_get_seqnum(loop_event->dev), loop_event->pid, exitstatus, time(NULL) - loop_event->queue_time); loop_event->exitstatus = exitstatus; + if (debug_trace) + printf("exit %s (%llu)\n", + udev_device_get_syspath(loop_event->dev), + udev_device_get_seqnum(loop_event->dev)); event_queue_delete(loop_event); + childs--; - /* there may be events waiting with the same devpath */ + /* there may be dependent events waiting */ run_exec_q = 1; return; } @@ -690,8 +669,6 @@ int main(int argc, char *argv[]) fprintf(stderr, "cannot open /dev/null\n"); err(udev, "cannot open /dev/null\n"); } - if (fd > STDIN_FILENO) - dup2(fd, STDIN_FILENO); if (write(STDOUT_FILENO, 0, 0) < 0) dup2(fd, STDOUT_FILENO); if (write(STDERR_FILENO, 0, 0) < 0) @@ -755,8 +732,7 @@ int main(int argc, char *argv[]) err(udev, "error reading rules\n"); goto exit; } - udev_list_init(&running_list); - udev_list_init(&exec_list); + udev_list_init(&event_list); export_initial_seqnum(udev); if (daemonize) { @@ -779,7 +755,8 @@ int main(int argc, char *argv[]) } /* redirect std{out,err} */ - if (!debug) { + if (!debug && !debug_trace) { + dup2(fd, STDIN_FILENO); dup2(fd, STDOUT_FILENO); dup2(fd, STDERR_FILENO); } @@ -840,7 +817,7 @@ int main(int argc, char *argv[]) inotify_add_watch(inotify_fd, udev_get_rules_path(udev), IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE); } else { - char filename[PATH_MAX]; + char filename[UTIL_PATH_SIZE]; inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d", IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE); @@ -858,17 +835,20 @@ int main(int argc, char *argv[]) else err(udev, "inotify_init failed: %m\n"); - /* maximum limit of forked childs */ - value = getenv("UDEVD_MAX_CHILDS"); - if (value) - max_childs = strtoul(value, NULL, 10); - else { + /* in trace mode run one event after the other */ + if (debug_trace) { + max_childs = 1; + } else { int memsize = mem_size_mb(); if (memsize > 0) max_childs = 128 + (memsize / 4); else max_childs = UDEVD_MAX_CHILDS; } + /* possibly overwrite maximum limit of executed events */ + value = getenv("UDEVD_MAX_CHILDS"); + if (value) + max_childs = strtoul(value, NULL, 10); info(udev, "initialize max_childs to %u\n", max_childs); maxfd = udev_ctrl_get_fd(udev_ctrl);