Re: Linux 2.6.34-rc4

["Justin P. mattock" <justinmattock@gmail.com>]

On 04/12/2010 07:16 PM, Linus Torvalds wrote:
>
> It's been two weeks rather than the usual one, because we've been hunting
> a really annoying VM regression that not a lot of people seem to have
> seen, but I didn't want to release an -rc4 with it. So we had the choice
> of either reverting all the anon-vma scalability improvements, or finding
> out exactly what caused the regression and fixing it.
>
> And we got pretty close to the point where I was going to just revert it
> all.
>
> Absolutely _huge_ kudos to Borislav Petkov who reported the problem and
> was able to not just reliably reproduce it, but also test new patches to
> try to narrow things down at a moments notice. The thing took ten days of
> emails flying back and forth, and Borislav was there all the time, day and
> night, through several patches that tried to fix it (several real bugs,
> but not the one he hit) and lots of patches to just add instrumentation to
> get us nearer to the cause of the problem.
>
> And finally, today, confirmation that we actually nailed the problem. So
> if anybody has been seeing a oops (or sometimes a GP fault) in
> page_referenced(), that should be gone now.
>
> Anyway, there's certainly been other things going on too, but the VM
> regression was the one that kept me personally busy, and held up the
> release.
>
> The bulk of the changes come from drivers - a new network driver (cxgb4),
> but also updates to the radeon and nouveau drivers.
>
> And then there is the random updates everywhere. The appended shortlog is
> about as good an overview as anything.
>
> 		Linus
>
> ---


I noticed the vm discussion, but had no idea what was going on.
In any case that's pretty cool to see(read). Love to see the hard
work and collaboration to fix a problem.

cheers,

Justin P. Mattock