On 03/31/2010 01:40 PM, Andrew Morton wrote: > On Fri, 26 Mar 2010 01:11:00 +0530 > Rabin Vincent <rabin@xxxxxx> wrote: > >> > On latest git, I'm seeing "start_kernel(): bug: interrupts were enabled >> > early" messages on ARM (sample log below). >> > >> > This appears to be caused by: >> > >> > start_kernel -> radix_tree_init -> kmem_cache_create (slub) -> >> > down_write -> __down_write (lib/rwsem-spinlock.c) -> spin_unlock_irq >> > >> > radix_tree_init was moved earlier by: >> > >> > commit 773e3eb7b81e5ba13b5155dfb3bb75b8ce37f8f9 >> > Author: Yinghai Lu <yinghai@xxxxxxxxxx> >> > Date: Wed Feb 10 01:20:33 2010 -0800 >> > >> > init: Move radix_tree_init() early >> > >> > Prepare for using radix trees in early_irq_init(). >> > >> > Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx> >> > LKML-Reference: <1265793639-15071-30-git-send-email-yinghai@xxxxxxxxxx> >> > Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxx> >> > > That's going to be hard to fix. > > Once upon a time, enabling interrupts too early in boot would kill > powerpc boxes stone dead. From the lack of noise I assume that this is > not happening in current kernels for some reason. > > We have two checks in start_kernel(): > > if (!irqs_disabled()) { > printk(KERN_WARNING "start_kernel(): bug: interrupts were " > "enabled *very* early, fixing it\n"); > local_irq_disable(); > } > rcu_init(); > radix_tree_init(); > /* init some links before init_ISA_irqs() */ > early_irq_init(); > init_IRQ(); > prio_tree_init(); > init_timers(); > hrtimers_init(); > softirq_init(); > timekeeping_init(); > time_init(); > profile_init(); > if (!irqs_disabled()) > printk(KERN_CRIT "start_kernel(): bug: interrupts were " > "enabled early\n"); > > perhaps the second one isn't needed? Perhaps no architecture requires > that local interrupts be disabled across the above initialisations? spin_unlock_irq from arm is different from other archs? YH -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html