Re: [Bug #13178] Booting very slow

Martin Knoblauch
2009-05-20T10:14:36Z

------------------------------------------------------
Martin Knoblauch
email: k n o b i AT knobisoft DOT de
www: http://www.knobisoft.de

----- Original Message ----
> From: Kay Sievers <kay.sievers-tD+1rO4QERM@public.gmane.org>
> To: Martin Knoblauch <spamtrap-Ys4E+72pFW0hFhg+JK9F0w@public.gmane.org>
> Cc: Rafael J. Wysocki <rjw-KKrjLPT3xs0@public.gmane.org>; Linux Kernel Mailing List <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>; Kernel Testers List <kernel-testers-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
> Sent: Tuesday, May 19, 2009 10:58:24 AM
> Subject: Re: [Bug #13178] Booting very slow
>
> On Tue, May 19, 2009 at 09:22, Martin Knoblauch wrote:
> >> > The issue is still open. It turns out that starting with 2.6.29-rc1
> >> /proc/mounts already has a "sysfs" line when entering the startup scripts
> from
> >> initrd. This breaks the RHEL4 firmware hotplug script.
> >>
> >> Is that possibly a missing/failing "umount /sys" _in_ initramfs, which
> >> leaves the sysfs entry in /proc/mounts behind, which then shows up as
> >> a duplicate when running in the real rootfs?
> >
> > could be. Remains the question, why it never showed up before 2.6.29. I
> compared my initrd images for 2.6.28 and 2.6.29-rc1, and they only differ in the
> module-binaries.
>
> I wouldn't be surprised if we are just "too fast" again now with the
> async stuff, for another piece of rather fragile userspace bootup
> logic, making some wrong assumptions. Are you compiling-in the modules
> for the root disk and the root filesystem?
>
> Cheers,
> Kay

timing may actually be the answer. I finally manged to bisect the thing and the first bad commit is this one:

|commit 1120f8b8169fb2cb51219d326892d963e762edb6
|Author: Stephen Hemminger <shemminger-ZtmgI6mnKB3QT0dZR+AlfA@public.gmane.org>
|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 <shemminger-ZtmgI6mnKB3QT0dZR+AlfA@public.gmane.org>
| Reviewed-by: Matthew Wilcox <willy-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
| Signed-off-by: Jesse Barnes <jbarnes-Y1mF5jBUw70BENJcbMCuUQ@public.gmane.org>

And no, the "cciss", "ext3" and "jbd" are modules in my intrd image.

I will continue the discussion under the original topic.

Cheers