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Re: [dm-devel] Fwd: 2.6.25-rc1 patch prevents booting on LVM-based devices



On Wed, 2008-02-20 at 11:20 -0500, Chuck Lever wrote:
> Begin forwarded message:
> > From: Chuck Lever <chuck lever oracle com>
> > Date: February 20, 2008 10:50:01 AM EST
> > To: dm-devel redhat com
> > Subject: 2.6.25-rc1 patch prevents booting on LVM-based devices
> >
> > Hello-
> >
> > I've got a Fedora 8 x86 test system that uses LVM volumes for all  
> > it's file systems except /boot.  After commit bdc80787, 2.6.24+  
> > doesn't boot on this system -- the LVM volume scan during start-up  
> > can no longer find any physical volumes on the system.
> >
> > I'm not sure whether this is an LVM issue, or something else is  
> > breaking during system init which prevents the LVM scan from  
> > working.  I need some help troubleshooting the problem.
> 
> Interestingly, if I build a non-tickless kernel, the problem goes away.
> 

Did you see this:
http://bugzilla.kernel.org/show_bug.cgi?id=10021

Another guess would be the below change is affecting your low-level
driver in some way as to prevent devices from being discovered.  Is this
FC (qla2xxx) or something else?


> > bdc80787 is:
> >
> > commit bdc807871d58285737d50dc6163d0feb72cb0dc2
> > Author: H. Peter Anvin <hpa zytor com>
> > Date:   Fri Feb 8 04:21:26 2008 -0800
> >
> >     avoid overflows in kernel/time.c
> >
> >     When the conversion factor between jiffies and milli- or  
> > microseconds is
> >     not a single multiply or divide, as for the case of HZ == 300,  
> > we currently
> >     do a multiply followed by a divide.  The intervening result,  
> > however, is
> >     subject to overflows, especially since the fraction is not  
> > simplified (for
> >     HZ == 300, we multiply by 300 and divide by 1000).
> >
> >     This is exposed to the user when passing a large timeout to poll 
> > (), for
> >     example.
> >
> >     This patch replaces the multiply-divide with a reciprocal  
> > multiplication on
> >     32-bit platforms.  When the input is an unsigned long, there is  
> > no portable
> >     way to do this on 64-bit platforms there is no portable way to  
> > do this
> >     since it requires a 128-bit intermediate result (which gcc does  
> > support on
> >     64-bit platforms but may generate libgcc calls, e.g.  on 64-bit  
> > s390), but
> >     since the output is a 32-bit integer in the cases affected,  
> > just simplify
> >     the multiply-divide (*3/10 instead of *300/1000).
> >
> > and so on...
> >
> > --
> > Chuck Lever
> > chuck[dot]lever[at]oracle[dot]com
> >
> >
> >
> 
> --
> Chuck Lever
> chuck[dot]lever[at]oracle[dot]com
> 
> 
> 
> --
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> dm-devel redhat com
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