clamp the max cpu.shares to the maximum value allowed by the kernel.
It is not an issue when using cgroupfs, as the kernel will
anyway make sure the value is not out of range and automatically clamp
it, systemd has an additional check that prevents the cgroup creation.
Closes: https://github.com/kubernetes/kubernetes/issues/92855
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
Previously, it was possible for reusable CPUs and reusable devices (i.e.
those previously consumed by init containers) to not be reused by
subsequent init containers or app containers if the TopologyManager was
enabled. This would happen because hint generation for the
TopologyManager was not considering the reusable devices when it made
its hint calculation.
As such, it would sometimes:
1) Generate a hint for a differnent NUMA node, causing the CPUs and
devices to be allocated from that node instead of the one where the
reusable devices live; or
2) End up thinking there were not enough CPUs or devices to allocate and
throw a TopologyAffinity admission error
This patch fixes this by ensuring that reusable CPUs and devices are
considered as part of TopologyHint generation. This frunctionality is
difficult to unit test since it spans multiple components, but an e2e
test will be added in a subsequent patch to test this functionality.
use the new libcontainer feature of skipping setting the devices
cgroup. This is necessary on cgroup v2 to avoid leaking a eBPF
program every time the cgroup is re-configured.
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
Previously, we didn't check the contents of the result after calling out
to the plugin endpoint. This could have resulted in errors if the plugin
returned either 'nil' or an empty result. This patch fixes this.
Previously, we were passing the variable 'devices' to this function,
when we should have been passing 'allocated'. This bug crept in due to a
variable name change that didn't propogate its way through the entire
function. The tests added in the previous commit would have caught this.
The expectation is that exclusive CPU allocations happen at pod
creation time. When a container restarts, it should not have its
exclusive CPU allocations removed, and it should not need to
re-allocate CPUs.
There are a few places in the current code that look for containers
that have exited and call CpuManager.RemoveContainer() to clean up
the container. This will end up deleting any exclusive CPU
allocations for that container, and if the container restarts within
the same pod it will end up using the default cpuset rather than
what should be exclusive CPUs.
Removing those calls and adding resource cleanup at allocation
time should get rid of the problem.
Signed-off-by: Chris Friesen <chris.friesen@windriver.com>
With the old strategy, it was possible for an init container to end up
running without some of its CPUs being exclusive if it requested more
guaranteed CPUs than the sum of all guaranteed CPUs requested by app
containers. Unfortunately, this case was not caught by our unit tests
because they didn't validate the state of the defaultCPUSet to ensure
there was no overlap with CPUs assigned to containers. This patch
updates the strategy to reuse the CPUs assigned to init containers
across into app containers, while avoiding this edge case. It also
updates the unit tests to now catch this type of error in the future.
The cpumanager file-based state backend was obsoleted since few
releases, aving the cpumanager moved to the checkpointmanager common
infrastructure.
The old test checking compatibility to/from the old format is
also no longer needed, because the checkpoint format is stable
(see
https://github.com/kubernetes/kubernetes/tree/master/pkg/kubelet/checkpointmanager).
Signed-off-by: Francesco Romani <fromani@redhat.com>
