Re: [stable] Regression in 2.6.32.2: segfault on halt

[Mike Galbraith <efault@gmx.de>]

On Sun, 2009-12-20 at 14:06 +0100, Willy Tarreau wrote:
> Hi Holger,
> 
> On Sun, Dec 20, 2009 at 12:55:50PM +0100, Holger Hoffstätte wrote:
> > Willy Tarreau wrote:
> > > On Sat, Dec 19, 2009 at 04:10:49PM +0100, Holger Hoffstaette wrote:
> > >> After updating to 2.6.32.2 last night (using same config from .32.1) I
> > >> noticed that "halt" now trips during shutdown and won't power the
> > >> machine down any longer. This happens reproducibly on two completely
> > >> different machines, so it looks like a generic problem and regression,
> > >> since it did not happen in .32.1. Note that "reboot" works as expected -
> > >> only "halt" crashes.
> > > 
> > > I have it working fine here. So your config helps to reproduce the issue.
> > > Care to post it ?
> > 
> > Attached, if it matters. However I managed to find some time with a spare
> > machine and always wanted to try bisect, so that's what I did - apparently
> > successfully:
> > 
> > root>git bisect bad
> > 37ed2d7007a65874850f3e357c095806c3756330 is the first bad commit
> > commit 37ed2d7007a65874850f3e357c095806c3756330
> > Author: Mike Galbraith <efault@gmx.de>
> > Date:   Wed Nov 4 17:53:50 2009 +0100
> > 
> >     sched: Rate-limit newidle
> 
> Interesting, because I saw this one too while digging the patch preview
> for the word "migration" which appeared in your trace. But these changes
> did not look suspicious (no obvious invalid pointer dereference for
> instance).
> 
> CCing Mike who may have an idea.

Thanks Willy.  No, no idea.  I can't see how this can possibly cause a
crash, but will try building with his config to see what happens.

	-Mike