thread__namespaces_lock
down_write(thread__namespaces_lock(thread));
up_write(thread__namespaces_lock(thread));
exit_rwsem(thread__namespaces_lock(thread));
down_read(thread__namespaces_lock(thread));
up_read(thread__namespaces_lock(thread));
down_write(thread__namespaces_lock(thread));
up_write(thread__namespaces_lock(thread));
init_rwsem(thread__namespaces_lock(thread));