diff options
| -rw-r--r-- | src/core/manager.h | 3 | ||||
| -rw-r--r-- | src/core/mount.c | 80 |
2 files changed, 7 insertions, 76 deletions
diff --git a/src/core/manager.h b/src/core/manager.h index 9f8fc4643..bce8020cf 100644 --- a/src/core/manager.h +++ b/src/core/manager.h @@ -227,9 +227,6 @@ struct Manager { /* Data specific to the mount subsystem */ struct libmnt_monitor *mount_monitor; sd_event_source *mount_event_source; - sd_event_source *mount_timeout_source; - usec_t mount_last_read_usec; - usec_t mount_last_duration_usec; /* Data specific to the swap filesystem */ FILE *proc_swaps; diff --git a/src/core/mount.c b/src/core/mount.c index cfdcc6e6f..ead9bc1f4 100644 --- a/src/core/mount.c +++ b/src/core/mount.c @@ -55,7 +55,6 @@ static const UnitActiveState state_translation_table[_MOUNT_STATE_MAX] = { static int mount_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata); static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata); -static int mount_dispatch_proc_self_mountinfo_timer(sd_event_source *source, usec_t usec, void *userdata); static bool MOUNT_STATE_WITH_PROCESS(MountState state) { return IN_SET(state, @@ -1666,7 +1665,6 @@ static int mount_load_proc_self_mountinfo(Manager *m, bool set_flags) { static void mount_shutdown(Manager *m) { assert(m); - m->mount_timeout_source = sd_event_source_unref(m->mount_timeout_source); m->mount_event_source = sd_event_source_unref(m->mount_event_source); mnt_unref_monitor(m->mount_monitor); @@ -1782,50 +1780,13 @@ fail: mount_shutdown(m); } -static void mount_process_proc_self_mountinfo(Manager *m); - static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) { + _cleanup_set_free_free_ Set *around = NULL, *gone = NULL; Manager *m = userdata; + const char *what; + Iterator i; + Unit *u; int r; - usec_t next_read = usec_add(m->mount_last_read_usec, - m->mount_last_duration_usec * 10); - - if (now(CLOCK_MONOTONIC) < next_read) { - /* The (current) API for getting mount events from the Linux kernel - * involves getting a "something changed" notification, and then having - * to re-read the entire /proc/self/mountinfo file. When there are lots - * of mountpoints, this file is large and parsing it can take noticeable - * time. As most of the file won't have changed, this can be seen as wasted time. - * If there is a "mount storm" such as 1000 mount points being created - * in quick succession, this will result in 1000 successive notification. - * If we respond to every notification, we will do quadratically more work - * than if we respond just once after all the notifications have arrived. - * In this (pathological) case, a delay in scheduling would actually - * improve throughput as we would combine notifications and parse - * the file less often. We cannot expect the scheduler to notice - * this pathology without help. - * So when the rate of notifications means we are spending more than - * 10% of real time handling them, we set a timer and stop listening - * to notifications for a while. - * If/when Linux provides an API which provides only details of what - * has changed, this rate-limiting can be removed. - */ - - r = sd_event_source_set_enabled(source, SD_EVENT_OFF); - if (r < 0) - log_warning_errno(r, "Failed to disable monitoring of /proc/self/mounting, ignoring: %m"); - if (!m->mount_timeout_source) { - r = sd_event_add_time(m->event, &m->mount_timeout_source, - CLOCK_MONOTONIC, - next_read, - 0, - mount_dispatch_proc_self_mountinfo_timer, - m); - if (r < 0) - log_warning_errno(r, "Failed to set timeout to reread /proc/self/mounting, ignoring: %m"); - } - return 0; - } assert(m); assert(revents & EPOLLIN); @@ -1853,40 +1814,13 @@ static int mount_dispatch_io(sd_event_source *source, int fd, uint32_t revents, return 0; } - mount_process_proc_self_mountinfo(m); - return 0; -} - -static int mount_dispatch_proc_self_mountinfo_timer(sd_event_source *source, usec_t usec, void *userdata) { - Manager *m = userdata; - int r; - - r = sd_event_source_set_enabled(m->mount_event_source, SD_EVENT_ON); - if (r < 0) - log_warning_errno(r, "Failed to reenable /proc/self/mountinfo monitor, ignoring: %m"); - m->mount_timeout_source = sd_event_source_unref(source); - mount_process_proc_self_mountinfo(m); - return 0; -} - -static void mount_process_proc_self_mountinfo(Manager *m) { - _cleanup_set_free_free_ Set *around = NULL, *gone = NULL; - const char *what; - Iterator i; - Unit *u; - int r; - - m->mount_last_read_usec = now(CLOCK_MONOTONIC); - /* If an error occurs, assume 10ms */ - m->mount_last_duration_usec = 10 * USEC_PER_MSEC; - r = mount_load_proc_self_mountinfo(m, true); if (r < 0) { /* Reset flags, just in case, for later calls */ LIST_FOREACH(units_by_type, u, m->units_by_type[UNIT_MOUNT]) MOUNT(u)->proc_flags = 0; - return; + return 0; } manager_dispatch_load_queue(m); @@ -1974,8 +1908,8 @@ static void mount_process_proc_self_mountinfo(Manager *m) { /* Let the device units know that the device is no longer mounted */ device_found_node(m, what, 0, DEVICE_FOUND_MOUNT); } - m->mount_last_duration_usec = usec_sub_unsigned(now(CLOCK_MONOTONIC), - m->mount_last_read_usec); + + return 0; } static void mount_reset_failed(Unit *u) { |