Re: [Xen-devel] Hypervisor crash(!) on xl cpupool-numa-split
On 01/28/11 12:07, Andre Przywara wrote:
Juergen Gross wrote:
On 01/28/11 00:18, Andre Przywara wrote:
when I boot my machine without restricting Dom0 (dom0_mem=
dom0_max_vcpus=) I get an _hypervisor_ crash when I run
# xl cpupool-numa-split
If Dom0's resources are limited on the Xen cmdline, everything works
The crashdump points to a scheduling problem with weights, so I assume
the NUMA distribution algorithm some fools the hypervisor completely.
I will investigate this further tomorrow, but maybe someone has some
I've seen this once with an older cpupool version on a 24 processor
It was NOT related to NUMA, but did occur only on reboot after a Dom0
The machine had an init script creating a cpupool and populating it with
cpus. The machine was in a panic loop due to the BUG in sched_acct
it was resetted manually. After the reset the problem was gone.
As I was never able to reproduce the problem later (the same software is
running on dozens of machines!), I assumed there was a problem related to
the first Dom0 panic, may be some destroyed BIOS tables.
Can the crash be reproduced easily?
If I don't specify dom0_max_vcpus= and dom0_mem= on the Xen cmdline, I
can reliably trigger the crash with xl cpupool-numa-split.
Omitting dom0_max_vcpus only does not suffice.
Do I understand correctly?
No crash with only dom0_max_vcpus= and no crash with only dom0_mem= ?
Could you try this patch?
diff -r b59f04eb8978 xen/common/schedule.c
--- a/xen/common/schedule.c Fri Jan 21 18:06:23 2011 +0000
+++ b/xen/common/schedule.c Fri Jan 28 12:42:46 2011 +0100
@@ -1301,7 +1301,9 @@ void schedule_cpu_switch(unsigned int cp
idle = idle_vcpu[cpu];
ppriv = SCHED_OP(new_ops, alloc_pdata, cpu);
+ BUG_ON(ppriv == NULL);
vpriv = SCHED_OP(new_ops, alloc_vdata, idle, idle->domain->sched_priv);
+ BUG_ON(vpriv == NULL);
Juergen Gross Principal Developer Operating Systems
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