Re: start_kernel(): bug: interrupts were enabled early

Andrew Morton
2010-03-31T22:50:56Z

On Thu, 01 Apr 2010 09:37:51 +1100
Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:

> On Wed, 2010-03-31 at 14:57 -0700, H. Peter Anvin wrote:
> >
> > The question still remains what the incremental cost is of doing
> > irqsave/irqrestore.
>
> The only other option is to have local_irq_enable() check a global
> (system_state ?) before enabling. Almost as gross ...
>

Add an irq-disable-depth counter to the task_struct, fix all the bugs
which that exposes..

But these things are all utterly gross. The bottom line is that
radix_tree_init() is manifestly unsuited to being called with local
interrupts disabled. 773e3eb7b81e5ba13b5155dfb3bb75b8ce37f8f9 was just
a wrong patch.