RPI-B VM panic

[Hans Petter Selasky]

On 06/12/14 19:12, Alan Cox wrote:
> On 06/12/2014 01:03, Hans Petter Selasky wrote:
>> On 06/11/14 22:47, Alan Cox wrote:
>>>
>>> On Jun 11, 2014, at 3:45 PM, Hans Petter Selasky wrote:
>>>
>>>> On 06/11/14 22:20, Alan Cox wrote:
>>>>>
>>>>> On Jun 11, 2014, at 3:07 PM, Hans Petter Selasky wrote:
>>>>>
>>>>>> kernel:     file format elf32-littlearm
>>>>>>
>>>>>
>>>>> Then this problem is unrelated to the one that I just fixed.  It's
>>>>> also not a problem that I've seen before.
>>>>
>>>> It is happening after your recent patches to -current, optimising
>>>> the "page ordering". Happens every now and then during boot when
>>>> stack is growing looks like.
>>>
>>> More precisely, which commit is that?
>>>
>>
>>> commit 7d20e37fb658b0e2cd7f3c13dac8022e0e866a21
>>> Author: alc <alc at FreeBSD.org>
>>> Date:   Sun May 12 16:50:18 2013 +0000
>>>
>>>      Refactor vm_page_alloc()'s interactions with
>>> vm_reserv_alloc_page() and
>>>      vm_page_insert() so that (1) vm_radix_lookup_le() is never called
>>> while the
>>>      free page queues lock is held and (2) vm_radix_lookup_le() is
>>> called at most
>>>      once.  This change reduces the average time that the free page
>>> queues lock
>>>      is held by vm_page_alloc() as well as vm_page_alloc()'s average
>>> overall
>>>      running time.
>>>
>>>      Sponsored by:       EMC / Isilon Storage Division
>>>
>>
>>
>
> That's not exactly a recent commit.  It was 13 months ago.  And, this
> code is exercised by all page allocations except for page table pages
> and uma_small_alloc().
>
> What this assertion is telling us is that somewhere else we have screwed
> up the vm object to which we are now trying to allocate a page.
>
> Try the attached patch.  It will provide additional information the next
> time that the assertion fails.
>

Here you go:

> panic: vm_page_insert_after: msucc 0xc0993e50 (0) doesn't succeed pindex 4
> object 0xc1a2b140 type 0
> KDB: enter: panic
> [ thread pid 18 tid 100052 ]
> Stopped at      $d:     ldrb    r15, [r15, r15, ror r15]!
> db>


--HPS