Kernel memory is not allowed to be updated if container is
running, it's not actually a precise kernel limitation.
Before kernel version 4.6, kernel memory will not be accounted
until kernel memory limit is set, if a container created with
kernel memory initialized, kernel memory is accounted as soon
as process created in container, so kernel memory limit update
is allowed afterward. If kernel memory is not initialized,
kernel memory consumed by processes in container will not be
accounted, so we can't update the limit because the account
will be wrong.
So update kernel memory of a running container with kernel memory
initialized is allowed, we should soften the limitation by docker.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Upstream-commit: 08c7075c403b86111b2c393b49075a81a1d2263f
Component: engine
1a97e07ac0
