> -----Original Message-----
> From: Magnus Damm [mailto:[EMAIL PROTECTED]
> Sent: 2007年1月31日 13:58
> To: Zou, Nanhai
> Cc: Jay Lan; Magnus Damm; linux-ia64@vger.kernel.org; Luck, Tony;
> fastboot@lists.osdl.org
> Subject: Re: [Fastboot] [PATCH] kexec: Avoid migration of already disabled 
> irqs
> (ia64)
> 
> Hi Nan hai,
> 
> On 1/31/07, Zou, Nanhai <[EMAIL PROTECTED]> wrote:
> > > On 1/31/07, Jay Lan <[EMAIL PROTECTED]> wrote:
> > > > Magnus Damm wrote:
> > > > > kexec: Avoid migration of already disabled irqs (ia64)
> > > > >
> > > > > This patch fixes up ia64 kexec support for HP rx2620 hardware. It does
> this
> > > > > by skipping migration of already disabled irqs. This is most likely
> a problem
> > > > > on other ia64 platforms as well, but I've only tested this on one 
> > > > > machine
> > > > > so far.
> > > >
> > > > I have not seen this problem on SN systems.
> > >
> > > Ok, thanks. Let me give you more details.
> > >
> > > When I perform "kexec -e" the following output appears on my serial
> > > console (with my patch applied).
> >
> >  This patch is correct I think. I assume you will also see this bug when 
> > trying
> to offline a CPU by echo 0 > /sys/devices/system/cpu/cpuX/online
> 
> You are right, I can trigger the bug that way too.
> And the bug goes away with the patch. Excellent!
> 
> > However it will not be triggered in crash dump case which has been tested
> heavily on different kind of platforms. We do not migrate IRQ at the time of
> crash. I guess that is why Jay has never seen it on SN platforms.
> 
> Booting into a crash kernel does not seem to work on this ia64 box
> unfortunately. I'm about to investigate why, but I thought trying and
> fixing kexec was a good first step.
> 
  That is probably caused by HP's IOMMU engine not shutting down at crash 
time...., 
Please try add machvec=dig option for the crash dump kernel.
  However we still need to find a light way to correctly shutdown IOMMU engine 
on those HP platforms.

Thanks
Zou Nan hai
> Thanks for the help!

> 
> / magnus

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