From: Thibaut VARENE Booting 2.6.21-rc3-g45592145 I noticed the following on one of my machines in the bootlog: io scheduler noop registered<6>Time: jiffies clocksource has been installed. io scheduler deadline registered (default) Looking at block/elevator.c, it appears that elv_register() uses two consecutive printks in a non-atomic way, leading to the above glitch. The attached trivial patch fixes this issue, by using a single printk. Signed-off-by: Thibaut VARENE Signed-off-by: Andrew Morton --- block/elevator.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff -puN block/elevator.c~make-elv_register-output-atomic block/elevator.c --- a/block/elevator.c~make-elv_register-output-atomic +++ a/block/elevator.c @@ -964,17 +964,18 @@ void elv_unregister_queue(struct request int elv_register(struct elevator_type *e) { + char *def = ""; spin_lock_irq(&elv_list_lock); BUG_ON(elevator_find(e->elevator_name)); list_add_tail(&e->list, &elv_list); spin_unlock_irq(&elv_list_lock); - printk(KERN_INFO "io scheduler %s registered", e->elevator_name); if (!strcmp(e->elevator_name, chosen_elevator) || (!*chosen_elevator && !strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED))) - printk(" (default)"); - printk("\n"); + def = " (default)"; + + printk(KERN_INFO "io scheduler %s registered%s\n", e->elevator_name, def); return 0; } EXPORT_SYMBOL_GPL(elv_register); _