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

[Pavel Emelyanov]

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?

> 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>
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