[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [BUG] Redhat-6.4_64bit-guest kernel panic with cpu-pass
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [BUG] Redhat-6.4_64bit-guest kernel panic with cpu-passthrough and guest numa |
Date: |
Mon, 01 Dec 2014 10:48:26 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 |
On 28/11/2014 03:38, Gonglei wrote:
>> > Can you find what line of kernel/sched.c it is?
> Yes, of course. See below please:
> "sgs->avg_load = (sgs->group_load * SCHED_LOAD_SCALE) / group->cpu_power; "
> in update_sg_lb_stats(), file sched.c, line 4094
> And I can share the cause of we found. After commit 787aaf57(target-i386:
> forward CPUID cache leaves when -cpu host is used), guest will get cpu cache
> from host when -cpu host is used. But if we configure guest numa:
> node 0 cpus 0~7
> node 1 cpus 8~15
> then the numa nodes lie in the same host cpu cache (cpus 0~16).
> When the guest os boot, calculate group->cpu_power, but the guest find thoes
> two different nodes own the same cache, then node1's group->cpu_power
> will not be valued, just is the initial value '0'. And when vcpu is scheduled,
> division by 0 causes kernel panic.
Thanks. Please open a Red Hat bugzilla with the information, and Cc
Larry Woodman <address@hidden> who fixed a few instances of this in
the past.
Paolo
- Re: [Qemu-devel] [BUG] Redhat-6.4_64bit-guest kernel panic with cpu-passthrough and guest numa,
Paolo Bonzini <=