Container runtimes like CRI-O and containerd utilize the freezer cgroup
to create a consistent snapshot of container root filesystem (rootfs)
changes. In this case, the container is frozen before invoking CRIU.
After CRIU successfully completes, a copy of the container rootfs diff
is saved, and the container is then unfrozen.
However, the `cuda-checkpoint` tool is not able to perform a 'lock'
action on frozen threads. To support GPU checkpointing with these
container runtimes, we need to unfreeze the cgroup and return it to its
original state once the checkpointing is complete.
To reflect this new behavior, the following changes are applied:
- `dont_use_freeze_cgroup(void)` -> `set_compel_interrupt_only_mode(void)`
- `bool freeze_cgroup_disabled` -> `bool compel_interrupt_only_mode`
- `check_freezer_cgroup(void)` -> `prepare_freezer_for_interrupt_only_mode(void)`
Note that when `compel_interrupt_only_mode` is set to `true`,
`compel_interrupt_task()` is used instead of `freeze_processes()`
to prevent tasks from running during `criu dump`.
Fixes: #2508
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
This patch extends the inventory image with a `plugins` field that
contains an array of plugins which were used during checkpoint,
for example, to save GPU state. In particular, the CUDA and AMDGPU
plugins are added to this field only when the checkpoint contains
GPU state. This allows to disable unnecessary plugins during restore,
show appropriate error messages if required CRIU plugin are missing,
and migrate a process that does not use GPU from a GPU-enabled system
to CPU-only environment.
We use the `optional plugins_entry` for backwards compatibility. This
entry allows us to distinguish between *unset* and *missing* field:
- When the field is missing, it indicates that the checkpoint was
created with a previous version of CRIU, and all plugins should be
*enabled* during restore.
- When the field is empty, it indicates that no plugins were used during
checkpointing. Thus, all plugins can be *disabled* during restore.
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
The presence of /dev/nvidiactl indicates that the system has a
compatible NVIDIA GPU driver installed and that the GPU is accessible to
the operating system.
Signed-off-by: Andrei Vagin <avagin@google.com>
Some plugins (e.g., CUDA) may not function correctly when processes are
frozen using cgroups. This change introduces a mechanism to disable the
use of freeze cgroups during process seizing, even if explicitly
requested via the --freeze-cgroup option.
The CUDA plugin is updated to utilize this new mechanism to ensure
compatibility.
Signed-off-by: Andrei Vagin <avagin@google.com>
When attempting to checkpoint a container with CUDA processes,
CRIU could fail with the following error:
Error (criu/cr-dump.c:1791): Timeout reached. Try to interrupt: 1
Error (cuda_plugin.c:143): cuda_plugin: Unable to read output of cuda-checkpoint: Interrupted system call
Error (cuda_plugin.c:384): cuda_plugin: PAUSE_DEVICES failed with
In this situation, the target process is locked, but CRIU fails due to
a timeout and exits with an error. We need to make sure that the target
PID is unlocked in such case.
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
When the cuda-checkpoint tool is not installed, execvp() is expected to
fail and return -1. In this case, we need to call exit() to terminate
the child process that was created earlier with fork().
Since CRIU can be used with applications that do not use CUDA, even
when the CUDA plugin is installed, this patch also updates the log
messages to show debug and warning (instead of error) when the
cuda-checkpoint tool is not found in $PATH.
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
Signed-off-by: Andrei Vagin <avagin@google.com>
CRIU provides two plugins for checkpoint/restore of GPU applications:
amdgpu and cuda. Both plugins use the `RESUME_DEVICES_LATE` hook to
enable restore:
CR_PLUGIN_REGISTER_HOOK(CR_PLUGIN_HOOK__RESUME_DEVICES_LATE, amdgpu_plugin_resume_devices_late)
CR_PLUGIN_REGISTER_HOOK(CR_PLUGIN_HOOK__RESUME_DEVICES_LATE, cuda_plugin_resume_devices_late)
However, CRIU currently does not support running more than one plugin
for the same hook. As a result, when both plugins are installed, the
resume function for CUDA applications is not executed. To fix this,
we need to make sure that both `plugin_resume_devices_late()` functions
return `-ENOTSUP` when restore is not supported.
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
Adding support for the NVIDIA cuda-checkpoint utility, requires the use of an
r555 or higher driver along with the cuda-checkpoint binary.
Signed-off-by: Jesus Ramos <jeramos@nvidia.com>
