Subject: Re: HEAD instability on Xen
To: Manuel Bouyer <firstname.lastname@example.org>
From: Antti Kantee <email@example.com>
Date: 11/18/2007 22:39:34
On Sun Nov 18 2007 at 21:19:15 +0100, Manuel Bouyer wrote:
> I've tested a kernel built from HEAD (which I didn't do for some time) and
> seeing panics when starting xend (this dom0 has only 64Mb RAM allocated).
> It's always a uvm_fault() on a kernel address, but the fault instruction
> varies. Here's a sample of a panic:
> Starting xend.
> uvm_fault(0xc09605c0, 0xc8028000, 1) -> 0xe
> fatal page fault in supervisor mode
> trap type 6 code 0 eip c03c8bdd cs 9 eflags 10246 cr2 0 ilevel 0
> kernel: supervisor trap page fault, code=0
> Stopped in pid 169.1 (python2.4) at netbsd:uvm_map_lookup_entry+0x4d: cmpl %edi,0x20(%ebx)
> db> tr
> uvm_map_lookup_entry(c5db0ac4,8063000,c7fa6690,1,0) at netbsd:uvm_map_lookup_entry+0x4d
> uvm_fault_internal(c5db0ac4,8063000,2,0,c04db079) at netbsd:uvm_fault_internal+0xdd
> trap() at netbsd:trap+0x415
Looks awfully lot like corrupted vm_maps for the newly created process.
But I don't know why this would be related to xen and specifically
What do you mean that the fault instruction varies? Is it still always
trying to access a vm_map_entry? I'm guessing the above example was
from line 1556 in uvm_map.c.
Anyway, just guessing really.
Antti Kantee <firstname.lastname@example.org> Of course he runs NetBSD
"la qualité la plus indispensable du cuisinier est l'exactitude"