[CRIU] lxc-checkpoint 1.1.5 works with criu 1.6.1 but not master

[Pavel Emelyanov]

On 01/14/2016 03:07 PM, Adrian Reber wrote:
> On Wed, Jan 13, 2016 at 04:18:31PM +0300, Pavel Emelyanov wrote:
>> On 01/07/2016 01:04 PM, Adrian Reber wrote:
>>> Hello Tycho,
>>>
>>> thanks for your answers.
>>>
>>> On Wed, Jan 06, 2016 at 07:15:25AM -0700, Tycho Andersen wrote:
>>>> Hi Adrian,
>>>>
>>>> On Tue, Jan 05, 2016 at 06:47:55PM +0100, Adrian Reber wrote:
>>>>> Running lxc-checkpoint works with CRIU 1.6.1 but not with today's
>>>>> master.
>>>>>
>>>>> I get the following dump.log with today's master:
>>>>>
>>>>> (00.000250) Probing sock diag modules
>>>>> (00.000280) Done probing
>>>>> (00.000283) ========================================
>>>>> (00.000286) Dumping processes (pid: 10794)
>>>>> (00.000287) ========================================
>>>>> (00.000289) Running pre-dump scripts
>>>>> (00.000315) Found anon-shmem device at 4
>>>>> (00.000321) Reset 16059's dirty tracking
>>>>> (00.000329) Warn  (mem.c:56): Can't reset 16059's dirty memory tracker (22)
>>>>> (00.000341) Unlock network
>>>>> (00.000347) Unfreezing tasks into 1
>>>>> (00.000352) Error (cr-dump.c:1578): Dumping FAILED.
>>>>
>>>> I've not seen this before. Based on a quick glance through the source,
>>>> looks like the write() to /proc/pid/clear_refs is failing with EINVAL,
>>>> which probably means your kernel is too old. Seems like this shouldn't
>>>> be a fatal failure, though, as lxc-checkpoint doesn't try to use any
>>>> memory tracking features.
>>>
>>> I have always seen the dirty memory tracking warning, but as it is a
>>> warning it has never been a problem before. It seems, however, that with
>>> the following commit:
>>>
>>> commit d10835c4ee0d0b1881b926708dee9877f5fb294d
>>> Author: Pavel Emelyanov <xemul at parallels.com>
>>> Date:   Tue Dec 15 22:25:09 2015 +0300
>>>
>>>     dump: Dont read prohibited kernel files
>>>
>>> criu now just aborts. Reverting this commits 'fixes' the broken master
>>> behaviour.
>>
>> :(
>>
>> Would you check whether the patch titled 
>> "[PATCH] kdat: Handle pagemaps with zeroed pfns"
>> from the mailing list fixes it?
> 
> Unfortunately not. I had to change the last line of context of that
> patch to get it applied, but a simple dump still fails:
> 
> # ./criu dump -D /tmp/3 -j -t `pidof minimal`  -v -v -v -v
> (00.000035) Probing sock diag modules
> (00.000072) Done probing
> (00.000074) ========================================
> (00.000076) Dumping processes (pid: 18737)
> (00.000078) ========================================
> (00.000081) Running pre-dump scripts
> (00.000106) Pagemap is fully functional
> (00.000136) Found anon-shmem device at 4
> (00.000141) Reset 20624's dirty tracking
> (00.000147) Warn  (mem.c:56): Can't reset 20624's dirty memory tracker (22)

Hm... Does your kernel lack support for soft-dirty tracking at all?

> (00.000160) Unlock network
> (00.000167) Unfreezing tasks into 1
> (00.000173) Error (cr-dump.c:1578): Dumping FAILED.
> 
> 		Adrian
> .
>