Re: [PATCH 07/19] x86/dumpstack: add IRQ_USABLE_STACK_SIZE define
From: Josh Poimboeuf
Date: Thu Jul 21 2016 - 21:48:24 EST
On Thu, Jul 21, 2016 at 03:01:10PM -0700, Andy Lutomirski wrote:
> On Thu, Jul 21, 2016 at 2:21 PM, Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:
> > For reasons unknown, the x86_64 irq stack starts at an offset 64 bytes
> > from the end of the page. At least make that explicit.
> This is a change in behavior -- see below. Please mention this in the
> > FIXME: Can we just remove the 64 byte gap? If not, at least document
> > why.
> I have no clue.
> > irq_stack_end = (unsigned long *)(per_cpu(irq_stack_ptr, cpu));
> > - irq_stack = (unsigned long *)(per_cpu(irq_stack_ptr, cpu) - IRQ_STACK_SIZE);
> > + irq_stack = (unsigned long *)(per_cpu(irq_stack_ptr, cpu) -
> > + IRQ_USABLE_STACK_SIZE);
> This is different.
If nobody knows the reason for it, I may just remove it. It doesn't
seem to blow anything up on my system. I tried digging through the git
history but it's been there since the beginning of git time.