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? I'll ask Rafael and Maciej to track this as a post-2.6.33 regression. -- 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