Comment 4 for bug 1234289

running strace on one of the treads shows the culprit:

poll([{fd=4, events=POLLIN}, {fd=8, events=POLLIN}], 2, 3998) = 0 (Timeout)
inotify_add_watch(8, "/etc/gdm", IN_MODIFY|IN_ATTRIB|IN_CLOSE_WRITE|IN_MOVED_FROM|IN_MOVED_TO|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF|IN_UNMOUNT|IN_ONLYDIR) = -1 ENOENT (No such file or directory)
poll([{fd=4, events=POLLIN}, {fd=8, events=POLLIN}], 2, 3996) = 0 (Timeout)
inotify_add_watch(8, "/etc/gdm", IN_MODIFY|IN_ATTRIB|IN_CLOSE_WRITE|IN_MOVED_FROM|IN_MOVED_TO|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF|IN_UNMOUNT|IN_ONLYDIR) = -1 ENOENT (No such file or directory)
poll([{fd=4, events=POLLIN}, {fd=8, events=POLLIN}], 2, 3996) = 0 (Timeout)
inotify_add_watch(8, "/etc/gdm", IN_MODIFY|IN_ATTRIB|IN_CLOSE_WRITE|IN_MOVED_FROM|IN_MOVED_TO|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF|IN_UNMOUNT|IN_ONLYDIR) = -1 ENOENT (No such file or directory)

for some reason it is polling every 4 seconds and adding a watch on a non-existent /etc/gdm directory