Re: [PATCH] ioapic: fix potential resume deadlock

[Ingo Molnar <mingo@elte.hu>]

* Suresh Siddha <suresh.b.siddha@intel.com> wrote:

> On Wed, 2011-05-11 at 09:15 -0700, Daniel J Blueman wrote:
> > Superb, this works, tested against 2.6.39-rc7 and addresses the "BUG:
> > sleeping function called from invalid context at mm/slub.c:824"
> > warning I was previously seeing. It would be good to get this fix into
> > 2.6.39-final if possible.
> > 
> > Tested-by: Daniel J Blueman <daniel.blueman@gmail.com>
> 
> Thanks Daniel for testing my quick patch. I have appended the complete
> patch which cleans up this code.
> 
> Ingo, This patch is relatively big (mostly removes the duplicate code
> and changes the location where we allocate ioapic_saved_data, so that
> this can be shared between interrupt-remapping and io-apic
> suspend/resume flows). May be this can go into 2.6.40-rc1 and probably
> go to 2.6.39-stable?

Could you please split it up into multiple steps? Commits with such a diffstat:

>  arch/x86/include/asm/io_apic.h |   21 ++----
>  arch/x86/kernel/apic/apic.c    |   49 ++++----------
>  arch/x86/kernel/apic/io_apic.c |  148 +++++++++++-----------------------------
>  3 files changed, 61 insertions(+), 157 deletions(-)

... rarely come without regressions attached, and it's a whole lot easier to 
figure out what's wrong with a small patch out of 3-4 than with such a big 
patch.

I'd suggest to make the end result exactly the same as this one big patch, so 
that we preserve Daniel's testing results.

Thanks,

	Ingo