Re: [tip:x86/irq] x86: Always use irq stacks

From: David Miller
Date: Wed Jul 14 2010 - 15:02:28 EST


From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Date: Wed, 14 Jul 2010 17:27:01 +0200 (CEST)

> On Wed, 14 Jul 2010, Christoph Hellwig wrote:
>
>> Turns out this wasn't a regression introduced by a commit, but it
>> happens when CONFIG_FUNCTION_GRAPH_TRACER is enabled. From a quick
>> look I have no idea why these would interact badly, especially as
>> CONFIG_FUNCTION_GRAPH_TRACER works fine with irq stacks if the
>> CONFIG_4KSTACKS options is set.
>
> So you're saying, that the problem appears when
> CONFIG_FUNCTION_GRAPH_TRACER is enabled w/o being used and that it
> exists prior to your patches with irq stacks and 8k stack size, but
> works with 4k stacks. That's definitely more than odd.

Some hard-coded check somewhere assuming kernel stack pages
won't straddle a page boundary?

Just a guess...
--
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/