Re: [PATCH] Add FUTEX_CMP_REQUEUE futex op
From: Arnd Bergmann
Date: Wed Jun 09 2004 - 16:57:57 EST
On Wednesday 09 June 2004 22:04, Pete Zaitcev wrote:
> Is it just me, or this could he above stand a use of STACK_FRAME_OVERHEAD
> instead of 160? I envision a time when Ulrich Weigand comes out with
> a gcc -fkernel, and at that time we'll need all such references
It wouldn't hurt, but even if we get -mkernel support in gcc, that doesn't
mean that the stack frame size has to change: You can easily have %r15
point to 160 bytes above the register save area without actually using all
that space for saving registers. The only thing that would need to change is
the location of the backchain pointer.
> Why not to place the necessary word outside of the struct?
> It just logically doesn't belong. Might be just as easy to
> do that mvc to other place.
That actually was what Martin tried in his first implementation (well, the
last one before the one he submitted). It didn't work out because some code
relied on the stack starting right after pt_regs. Martin can probably clarify
that on Friday.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/