Re: Analyzed/Solved/Bisected: Booting 2.6.30-rc2-git7 very slow

Martin Knoblauch
2009-05-20T11:01:47Z

----- Original Message ----

> From: Martin Knoblauch <knobi@knobisoft.de>
> To: Mike Galbraith <efault@gmx.de>
> Cc: Andrew Morton <akpm@linux-foundation.org>; viro@ZenIV.linux.org.uk; rjw@sisk.pl; linux-kernel@vger.kernel.org; tigran@aivazian.fsnet.co.uks; Kay Sievers <kay.sievers@vrfy.org>; Rafael J. Wysocki <rjw@sisk.pl>; shemminger@vyatta.com
> Sent: Wednesday, May 20, 2009 12:22:28 PM
> Subject: Re: Analyzed/Solved/Bisected: Booting 2.6.30-rc2-git7 very slow
>
> ----- Original Message ----
>
> > From: Mike Galbraith
> > To: Martin Knoblauch
> > Cc: Andrew Morton ; viro@ZenIV.linux.org.uk;
> rjw@sisk.pl; linux-kernel@vger.kernel.org; tigran@aivazian.fsnet.co.uk
> > Sent: Wednesday, May 6, 2009 10:37:45 AM
> > Subject: Re: Analyzed/Solved: Booting 2.6.30-rc2-git7 very slow
> >
> > On Wed, 2009-05-06 at 00:55 -0700, Martin Knoblauch wrote:
> >
> > > just to bring this back to my problem :-)
> >
> > Good idea :-)
> >
> > > Last week I reported that the "new" sysfs entry in /proc/mounts already
> comes
> > out of initrd. Does this ring a bell?
> > >
> > > http://lkml.indiana.edu/hypermail/linux/kernel/0904.3/03048.html
> >
> > Nope, no bells.
> >
> > The only thing I can suggest is that you try a bisection.
> >
> > -Mike
>
> OK, so I finally managed to bisect the issue down to the following commit. Not
> much that I can say about it. Someone else suggested that it might all be a
> question of timing. Might very well be. I will try it out on a system with a
> different SCSI/RAID controller. The failing system has an "Smart Array 6i"
> (cciss). "cciss", "ext3" and "jbd" are all modules coming from initrd.
>
> |commit 1120f8b8169fb2cb51219d326892d963e762edb6
> |Author: Stephen Hemminger
> |Date: Thu Dec 18 09:17:16 2008 -0800
> |
> | PCI: handle long delays in VPD access
> |
> | Accessing the VPD area can take a long time. The existing
> | VPD access code fails consistently on my hardware. There are comments
> |
> | Change the access routines to:
> | * use a mutex rather than spinning with IRQ's disabled and lock held
> | * have a much longer timeout
> | * call cond_resched while spinning
> |
> | Signed-off-by: Stephen Hemminger
> | Reviewed-by: Matthew Wilcox
> | Signed-off-by: Jesse Barnes
>

yup. Different hardware (IBM x3650 with aacraid) does not show the problem. So it seems to be timing related. I more and more tend to view this as "so what" and go along.

Cheers
Martin