Re: [NAK] Re: [PATCH -v2 9/9] ACPI, APEI, Generic Hardware Error Source POLL/IRQ/NMI notification type support

[Huang Ying <ying.huang@intel.com>]

Hi, Thomas,

On Tue, 2010-10-26 at 12:53 +0800, Thomas Gleixner wrote:
> B1;2401;0cLen,
> 
> On Mon, 25 Oct 2010, Len Brown wrote:
> 
> > >  NAKed-by: Ingo Molnar <mingo@elte.hu>
> > 
> > Everybody knows that Linux has a lot to learn about RAS.
> > 
> > I think to catch up, we need to play to Linux's strengths
> > of continuous improvement.  If we halt patches in this area
> > then we could wait forever for the "perfect design".
> 
> it's not about perfect design. It's about creating new user space
> ABIs. The patches introduce another error reporting user space ABI
> with an ad hoc "fits the needs" design.
> 
> This is my major point of objection. 
> 
> I agree that Linux needs improvement on the RAS side, but does this
> lack of features justify a new user space ABI which is totally
> disconnected to existing RAS facilities ?
> 
> No, it does not. It's not our problem that Intel wasted time on
> creating another character device driver to report errors to user
> space. The time spent to do so would have been sufficient to do a
> proper integration into the existing infrastructure.
> 
> I would not care at all if these patches would just introduce some
> weird in kernel interfaces as we can clean that up at will. But
> introducing a new user space ABI is setting the disconnect of RAS
> related facilities into stone.
> 
> From Kconfig:
> 
>   EDAC is designed to report errors in the core system.
>   These are low-level errors that are reported in the CPU or
>   supporting chipset or other subsystems:
>   memory errors, cache errors, PCI errors, thermal throttling, etc..
>   If unsure, select 'Y'.
> 
> So please explain why your error reporting is so different from the
> above that it justifies a separate facility. And you better come up
> with a real good explanation other than we looked at EDAC and it did
> not fit our needs.

As far as I know, EDAC guys plan to use some other "perfect interface"
in the future. So I think the current state is really waiting for the
"perfect design".

Best Regards,
Huang Ying