lkml.org 
[lkml]   [2011]   [Jul]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 5/6] x86: Remove useless unwinder backlink from irq regs saving
From
Date
On Mon, 04 Jul 2011 15:22:23 +0200, Frederic Weisbecker said:
> On Mon, Jul 04, 2011 at 08:29:08AM +0100, Jan Beulich wrote:
> > >>> On 02.07.11 at 18:29, Frederic Weisbecker <fweisbec@gmail.com> wrote:
> > > The unwinder backlink in interrupt entry is very useless.
> > > It's actually not part of the stack frame chain and thus is
> > > never used.
> >
> > I very much doubt this - see dump_trace()'s comment in its IRQ-stack
> > related code portion (and the corresponding use of irq_stack_end[-1]).
> >
> > Jan
>
> Good point. I misunderstood that.
>
> But then I believe I accidentally fixed it back in
> "x86: Don't use frame pointer to save old stack on irq entry" by
> pushing %rsi instead in the new stack. It contains the backlink to
> the old stack.
>
> If we keep the macro as-is, I'll add a comment to explain further
> what is involved there.

Ahh.. I was wondering why there wasn't suddenly a very lonely popq
out there... :)
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2011-07-06 00:25    [W:0.064 / U:0.080 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site