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

From: Martin Knoblauch
Date: Wed Apr 29 2009 - 05:34:45 EST



----- Original Message ----

> From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> To: Martin Knoblauch <knobi@xxxxxxxxxxxx>
> Cc: Rafael J. Wysocki <rjw@xxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx; efault@xxxxxx; tigran aivazian <tigran@xxxxxxxxxxxxxxxxxxxx>
> Sent: Wednesday, April 29, 2009 3:28:37 AM
> Subject: Re: Analyzed/Solved: Booting 2.6.30-rc2-git7 very slow
>
> On Fri, 24 Apr 2009 05:45:19 -0700 (PDT) Martin Knoblauch
> wrote:
>
> >
> >
> > OK, I just found the reason for both intel-ucode and tg3 failures. Apparently
> between 2.6.28 and 2.6.29 the mount of sysfs has subtely changed from:
> >
> > /sys /sys sysfs rw 0 0
> >
> > to:
> >
> > none /sys sysfs rw,relatime 0 0
>
> I assume that you're referring to the contents of /proc/mounts?
>
> > The "none" breaks the RHEL-4 provided hotplug script "firmware.agent" when it
> tries to parse the mount point for "/sys". As a result, the firmware loading is
> never properly finished and the driver(s) just timeout on the value in
> /sys/class/firmware/timeout. Bingo. Simple fix in user-pace possible - cool down
> Martin :-)
> >
> > Questions remains: was this intentional? It breaks existing userspace and
> should therefore be considered a regression - right? On the other hand, it will
> never be a problem for RHEL-4/5 kernels, unless the change in 2.6.29 gets
> backported. Any ideas?
>
> afaik that was unintentional and was probably a mistake.
>
> I wonder how we did that.

Actually, what breaks the RHEL-4.3 script is not the "none", but the duplicate lines in /proc/mounts that I reported earlier in the "regression" thread.

[root@lpsdm52]# grep sysfs /proc/mounts
none /sys sysfs rw,relatime 0 0
/sys /sys sysfs rw,relatime 0 0

One of them likely comes from the respective line in /etc/fstab, but where does the second one come from?


Cheers
Martin

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