Re: Cannot boot xen DomU > 2.6.23.1

[Jeremy Fitzhardinge <jeremy@goop.org>]

xming wrote:
> The symptom is (with a lot of subjective judgment) when there is a lot (or
> too quick) output on the console of the domU (hvc0 connected with either
> "xm crea file.cfg -c" or "xm cons id") the whole PV domU hangs. It will
> really hang at random places, sometimes right after init and sometime
> after I logged in and just generate some ouput (on hvc0) like "find /". IIRC
> I have never seen a hang before init.
>   

OK, I misunderstood your original report to mean that something was 
complaining about "too much" output.  You're saying that lots of console 
output seems to lock the domain.

I've had a report about heavy disk IO seems to lock up as well.  Perhaps 
they're both related to high event rates.  Do you think you could try an 
IO-intensive workload to see if you can get a similar lockup?

When the domain is locked up, what does /usr/lib/xen/bin/xenctx say?

Hm.  Rather than backing out the structure-change patch, could you try 
this workaround:

diff -r be3ca4e0e19e arch/x86/xen/enlighten.c
--- a/arch/x86/xen/enlighten.c	Thu Jan 17 14:25:07 2008 -0800
+++ b/arch/x86/xen/enlighten.c	Thu Jan 17 16:37:42 2008 -0800
@@ -95,7 +95,7 @@ struct shared_info *HYPERVISOR_shared_in
  *
  * 0: not available, 1: available
  */
-static int have_vcpu_info_placement = 1;
+static int have_vcpu_info_placement = 0;
 
 static void __init xen_vcpu_setup(int cpu)
 {


Reverting the structure shape could cause crashes or random data 
corruption, but it has the side-effect of disabling the vpu_info 
structure placement mechanism.  This patch disables it cleanly.

Thanks,
    J