Re: [dm-devel] AMD-Vi IO_PAGE_FAULTs and ata3.00: failed command: READ FPDMA QUEUED errors since Linux 4.0

[Milan Broz <mbroz@redhat.com>]

On 07/29/2015 08:17 AM, Ondrej Kozina wrote:
> On 07/28/2015 11:24 PM, Mike Snitzer wrote:
>>>
>>> I am willing to do tests if you have any idea to be tested - I can
>>> reproduce it quite easily.
>>
>> You can try disabling dm-crypt's parallelization by specifying these 2
>> features: same_cpu_crypt submit_from_crypt_cpus
>>
> 
> Hi,
> 
> please try adding follwoing cryptsetup perf. options while unlocking 
> your LUKS containers: --perf-submit_from_crypt_cpus and 
> --perf-same_cpu_crypt.
> 
> Perhaps focus on SSD disk as previous unresolved report mentioned SSD too

Just you need to use cryptsetup 1.6.7 version (older versions do not have this options yet).

Anyway, it seems strange that one patch triggers such a problem (leading to a conclusion
that the patch is wrong) but dm-crypt is know to reveal many problems in other systems
exactly this way...

The patches were tested on so many systems without problem that I really believe
the dmcrypt patch is just trigger for a bug elsewhere.

Anyway, if we can find configuration which fails here, I would like to help to find
the core problem... Papering here just means it will break data later elsewhere.

Thanks for testing it!
Milan