Determine any memory/CPU limitations from sysfs cgroup

[nealef]

Add capability to interrogate cgroup limitations when determining CP and memory limits

This code has been adapted from coreCLR. It has been modified from C++ but uses the same naming conventions in the event of a unified mechanism that can be shared between both runtimes being developed. The code has been tested on Ubuntu 20.04 and CentOS 7 with cgroupv1 and cgroupv2.

This code is required in the event of running runtime in a container as the current limitations being discovered by the mono runtime are purely for the machine and not in a container which may have lower quotas.

• src/mono/CMakeLists.txt

  • Set the HAVE_CGROUP_SUPPORT for Linux hosts

• src/mono/cmake/config.h.in

  • Place holder for HAVE_CGROU_SUPPORT definition

• src/mono/mono/metadata/icall.c

• src/mono/mono/sgen/sgen-marksweep.c

• src/mono/mono/sgen/sgen-simple-nursery.c

  • Use mono_cpu_limit() instead of mono_cpu_count()

• src/mono/mono/utils/CMakeLists.txt

  • Add mono-cgroup.c to the build

• src/mono/mono/utils/memfuncs.c

  • Call getRestrictedPhysicalMemoryLimit() or getPhyscalMemoryAvail()

• src/mono/mono/utils/memfuncs.h

  • Add prototypes for the new APIs

• src/mono/mono/utils/mono-cgroup.c

  • Code adapted from coreCLR to interrogate sysfs to determine any limitations on memory or CPU

• src/mono/mono/utils/mono-proclib.c

  • Add call to getCpuLimit()

• src/mono/mono/utils/mono-proclib.h

  • Add prototype for the new API

[naricc]

If this code is adapated from CoreCLR, is there a plan to share the code eventually, or need it all be duplicated?

[lambdageek]

@SamMonoRT I think we want to take a backport of this for net7. I don't think this will impact mobile or wasm. (But the "DOTNET_PROCESSOR_COUNT" support might be a nice thing to bring along on those platforms for diagnostic scenarios)

[SamMonoRT]

@SamMonoRT I think we want to take a backport of this for net7. I don't think this will impact mobile or wasm. (But the "DOTNET_PROCESSOR_COUNT" support might be a nice thing to bring along on those platforms for diagnostic scenarios)

Yes, once all suggestions are addressed and CI lanes look green, will issue a backport command.

[SamMonoRT]

@nealef - please let us know when all suggested changes are completed.

[nealef]

The only one missing is the explicit cast from strtol(). I am having VPN problems today so I haven't been able to push. All other suggestions should have been pushed.

[akoeplinger]

/backport to release/7.0

[github-actions]

Started backporting to release/7.0: https://github.com/dotnet/runtime/actions/runs/2965665895