Re: [BUG] "sched: Remove rq->lock from the first half of ttwu()"locks up on ARM

[Catalin Marinas]

On Sunday, 29 May 2011, Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> wrote:
> On Sun, May 29, 2011 at 11:21:19AM +0100, Catalin Marinas wrote:
>> To avoid extra per-thread flags, we could set a per-cpu variable in
>> switch_mm() so that we know what to switch the page tables to in the
>> post-switch hook.
>
> Why do we need to add more per-cpu stuff when we already have easy access
> to the thread flags?

It could work, I was thinking that we only get an mm structure in the
post-switch hook.

BTW, we currently have a per-cpu current_mm variable in context.c
because switch_mm() is called before switch_to() and the CPU may
receive an IPI to reset the ASID in this interval. But we can remove
it entirely if we set the ASID in the post-switch hook and run the
main switch code with interrupts disabled.


-- 
Catalin
--
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/