[Devel] [PATCH CRIU v5 0/1] dump/restore: Maintain proper start_time param from /proc/[pid]/stat for each task

[Valeriy Vdovin]

This patch addresses the problem of varying views on start time 
of a resumed process between container and host. From a container
point of view the resumed process is the same old process with
the same old start time, which hasn't changed after suspend/resume.
>From a host point of view the resumed process is just a new one
with a new start_time. Both the host and the container want to
see start time that is only relevant to their context.

To support that we should teach the output of of /proc/pid/stat
to show container-related value from container context and host-
related value from host context.

The patch introduces new field to task_struct that stores container-
related start time value. It will be seen in /proc/pid/stat in case
if it was requested by a task, that's in ve cgroup. 
Setting this field can be done with prctl only from host or a
container task with pseudosuper flag set.

At suspend this value is dumped by criu and at restore it's set back
from a dump by criu.

v5 changes:
- Added field to kerndat struct to check if prctl is supported by kernel
- Don't fail restore if kernel does not support start time fixing.
- Covered minor review comments.

Valeriy Vdovin (1):
  dump/restore: Maintain proper start_time param from /proc/[pid]/stat
    for each task

 criu/cr-dump.c          |  60 +++++++++++++++++++++++++++-
 criu/cr-restore.c       | 104 ++++++++++++++++++++++++++++++++++++------------
 criu/include/crtools.h  |  25 ++++++++++++
 criu/include/kerndat.h  |   1 +
 criu/include/prctl.h    |  10 +++++
 criu/include/restorer.h |   9 +++++
 criu/kerndat.c          |  20 ++++++++++
 criu/pie/restorer.c     |  25 ++++++++++++
 images/core.proto       |   1 +
 9 files changed, 228 insertions(+), 27 deletions(-)

-- 
1.8.3.1