Re: [PATCH] x86/pci: don't use crs for root if we only have one root bus

[Jaswinder Singh Rajput <jaswinder@kernel.org>]

On Thu, 2009-06-25 at 09:03 +0200, Ingo Molnar wrote:
> * Jesse Barnes <jbarnes@virtuousgeek.org> wrote:
> 
> > > [ There's a difference between "we're supposed to find and fix bugs
> > > in the -rc series", and "I release known-buggy -rc1's since we're
> > > supposed to fix it later". For similar reasons, I hate pulling
> > > known-buggy stuff during the merge window - it's ok if it shows
> > > itself to be buggy _later_, but if people send me stuff that they
> > > know is buggy as they send it to me, then that's a problem. ]
> > 
> > Yeah, 100% agreed.  I didn't hear any reports until after people 
> > started using your tree, so I think this case was handled 
> > correctly: push something that *seems* ok upstream, but with eyes 
> > wide open for the possibility we'd need to revert.
> 
> There's only one small gripe i have with the handling of it: the 
> timing. "9e9f46c: PCI: use ACPI _CRS data by default" was written 
> and committed on June 11th, two days _after_ the merge window 
> opened.
> 
> That's way too late for maybe-broken changes to x86 lowlevel details 
> (especially if it touches hw-environmental interaction - which is 
> very hard to test with meaningful coverage), and it's also pretty 
> much the worst moment to solicit testing from people who are busy 
> getting their stuff to Linus and who are busy testing out any of the 
> unexpected interactions and bugs.
> 
> So this was, to a certain degree, a predictable outcome. Trees in 
> the Linux "critical path" of testing (core kernel, x86, core 
> networking, very common drivers, PCI, driver core, VFS, etc.) should 
> generally try to cool down 1-2 weeks before the merge window - 
> because breakage there can do a lot of knock-on cascading damage. 
> Two weeks is not a lot of time and the effects of showstopper bugs 
> get magnified disproportionately.
> 

Yes, I was also thinking about this when I checked the commit date. And
totally agree with Ingo's suggestions.

Thanks,
--
JSR