Re: [PATCH 3/6] x86/mce: Add support for new MCA_SYND register

[Ingo Molnar <mingo@kernel.org>]

* Borislav Petkov <bp@alien8.de> wrote:

> On Fri, Jul 08, 2016 at 11:26:59AM +0200, Ingo Molnar wrote:
> > So why does neither the changelog nor the code comment actually _explain_ this and 
> > give aa bit of a background about what 'syndrome information' is and why we want 
> > to have kernel support for it?
> > 
> > This is why I hate kernel tooling that is not part of the kernel tree - the mcelog 
> > patch (hopefully ...) would tell us more about all this - but it's separate and 
> > this patch does not tell us anything ...
> 
> Ah, this is one of those omissions where we forgot to explain, sorry.
> How about this:
> 
> "The syndrome value is used to uniquely identify which bits of a
> reported ECC error are corrupted."

I'm not sure I can parse that: how can a reported error have bits corrupted?

Or is this about various details about the location of the error (normally 
contained in a 'struct mce' entry), and the 'syndrome value' further qualifies 
that information by telling us which fields of those records are reliable?

I.e. a bit more context would be nice. You cannot go wrong if you assume that 
readers of changelogs (and maintainers in particular) have the attention span
of a slightly retarded golden retriever.

> Do you want it as a comment in the code or in the commit message or both?

I'm fine with an add-on patch that adds a good explanation for all this to the 
code.

Thanks,

	Ingo