Re: [RFC GIT PULL] softirq: Consolidation and stack overrun fix

From: Benjamin Herrenschmidt
Date: Sun Sep 22 2013 - 01:01:42 EST


On Sun, 2013-09-22 at 14:39 +1000, Benjamin Herrenschmidt wrote:
> How do you do your per-cpu on x86 ? On powerpc we struggle because we
> try to dedicate a register (r13) to this PACA (the per-cpu offset hangs
> off it), but we constantly run into issues where gcc copies r13 to
> another register and then indexes off that, even accross
> preempt_enable/disable sections, or worst such as saving/restoring from
> the stack. We can't seem to get the compiler to treat it appropriately
> as volatile.

Also, do you have a half-decent way of getting to per-cpu from asm ?

Cheers,
Ben.


--
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/