[CRIU] [PATCH v2 0/4] aio: Support two versions of io_setup()

[Pavel Emelyanov]

On 05/20/2016 01:36 PM, Kirill Tkhai wrote:
> On 20.05.2016 12:46, Pavel Emelyanov wrote:
>> On 05/19/2016 04:11 PM, Kirill Tkhai wrote:
>>> Since e1bdd5f27a5b "aio: percpu reqs_available" kernel's io_setup()
>>> behaviour has changed. The syscall become multiply passed nr_events
>>> parameter twice to get on well with per-cpu aio.
>>
>> git describe says that the commit in question is 3.11-rc1++. Even if
>> we compensate for the errors git-describe might have due to merge
>> commits, in 3.11 aio was calculated in a new manner. But criu works
>> with aio only since 3.19, when it's become possible to remap rings.
>>
>> So why do we care for two versions?
> 
> Remap is backported to Virtuozzo 7 and RHEL7, just because of this. But if so,
> we'll backport e1bdd5f27a5b to Virtuozzo and recommend RHEL people
> to do the same.

Please.

However, patches 2 and 3 seem to be relevant even if we don't support
2 versions of ring size calculations, are they?

>>> CRIU supports only the e1bdd5f27a5b commit's logic, but it fails
>>> on older kernels. This patchset aims to support older logic too.
>>>
>>> v2: Take number of possible cpus in account
>>> ---
>>>
>>> Kirill Tkhai (4):
>>>       kdat: Calculate number of possible cpus
>>>       aio: Change pair of debug messages
>>>       aio: Refactor nr_req calculation
>>>       aio: Support two versions of io_setup()
>>>
>>>
>>>  criu/aio.c              |  112 ++++++++++++++++++++++++++++++++++++++++-------
>>>  criu/cr-restore.c       |    9 +++-
>>>  criu/include/aio.h      |    2 +
>>>  criu/include/kerndat.h  |    1 
>>>  criu/include/parasite.h |    2 -
>>>  criu/include/vma.h      |    1 
>>>  criu/kerndat.c          |   76 ++++++++++++++++++++++++++++++++
>>>  criu/pie/parasite.c     |    2 -
>>>  criu/pie/restorer.c     |    7 ++-
>>>  criu/proc_parse.c       |    1 
>>>  10 files changed, 187 insertions(+), 26 deletions(-)
>>>
>>> --
>>> Signed-by: Kirill Tkhai <ktkhai at virtuozzo.com>
>>> _______________________________________________
>>> CRIU mailing list
>>> CRIU at openvz.org
>>> https://lists.openvz.org/mailman/listinfo/criu
>>> .
>>>
>>
> .
>