containers may specify these cgroup values at runtime. This will allow
processes to change their priority to real-time within the container
when CONFIG_RT_GROUP_SCHED is enabled in the kernel. See #22380.
Also added sanity checks for the new --cpu-rt-runtime and --cpu-rt-period
flags to ensure that that the kernel supports these features and that
runtime is not greater than period.
Daemon will support a --cpu-rt-runtime flag to initialize the parent
cgroup on startup, this prevents the administrator from alotting runtime
to docker after each restart.
There are additional checks that could be added but maybe too far? Check
parent cgroups to ensure values are <= parent, inspecting rtprio ulimit
and issuing a warning.
Signed-off-by: Erik St. Martin <alakriti@gmail.com>
"--restart" and "--rm" are conflict options, if a container is started
with AutoRemove flag, we should forbid the update action for its Restart
Policy.
Signed-off-by: Zhang Wei <zhangwei555@huawei.com>
The memory should always be smaller than memoryswap,
we should error out with message that user know how
to do rather than just an invalid argument error if
user update the memory limit bigger than already set
memory swap.
Signed-off-by: Lei Jitang <leijitang@huawei.com>
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>
Add `--restart` flag for `update` command, so we can change restart
policy for a container no matter it's running or stopped.
Signed-off-by: Zhang Wei <zhangwei555@huawei.com>
It's used for updating properties of one or more containers, we only
support resource configs for now. It can be extended in the future.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Qiang Huang
Erik St. Martin
Zhang Wei
Lei Jitang
Sebastiaan van Stijn