VCL on Proxmox

[Joris L.]

Dear,

VCL is some neat software provided by the Mosix project. I hope to use it so i can combine multiple GPU into an OpenCL pipe. My question is if there are people who tried this out with Proxmox. I kind of expect it will allow me to use OpenCL from mutiple VM or LXC instead of just one.

http://www.mosix.cs.huji.ac.il/txt_about.html

 

[LnxBil]

Wow, i thought Mosix is dead ... I've used it back in 2003.

I kind of expect it will allow me to use OpenCL from mutiple VM or LXC instead of just one

Yes, I would also assume that the VM road with pcie passthrough should work.

 

[Joris L.]

Still a bit stuck on how to attain this. My assumption is to have one QEMU VM or LXC run VCL, whatever runs fastest. Then share the VCL with other VM and LXC. I own 2 opencl capable GPU for a test setup. What i seek to use this for is 1) IDS 2) Rendering 3) ?

Typically this sounds like an idea too good to be true, then again, based on what i read it could be these use case could work with minor modifications.

 

[LnxBil]

I think the technology is mainly for distributed setups, like a cluster of machines with GPUs and combining them to one big compute cluster.

If you have "only" on system, you can also combine them in one VM and don't need the network overlay.

 

[Joris L.]

VCL is an application independent from Mosix. Let me explain a bit.

What i was thinking about is to address an issue i see with PCI-passthrough. This works for just one VM at a time. Here VCL can come in.

When i think of facilitating OpenCL computing power to VMs i know one thing, one GPU per VM. Maybe more are possible, still stuck with one VM.

What VCL offers is to "collect" multiple OpenCL devices and offer them as a single device for compute. It is expected to do so transparently. Since i most often depend on open source solutions there is most likely the ability to make opencl implementations work with SuperCL provided for by VCL.

I hope this explains the setup i'm thinking about a bit more. Basically, VCL to collect OpenCL computing power, Proxmox to run VM and LXC which access the compute power collected using VCL (since VCL makes it avaible over the network)

 

[LnxBil]

Thank you, I see.

I hope it performs well. The main concern is bandwidth. I've been using GPGPU for over a decade now and the main problem is uploading and downloading data to/from the GPU memory (locally), because that is the bottleneck. You can optimize with streaming and such, but it remains the problem. How that works for your workload.

 

[Joris L.]

I simply rely on what i read thus far. My assumption is this may lead to either multiple LXC either multiple VM to use the same OpenCL devices.

Main features for VCL

Works with OpenCL devices from all vendors. Supports almost all OpenCL 1.1 (and 1.0) applications. Applications can use cluster-wide OpenCL devices. Transparent selection of devices. Supports multiple applications on the same cluster.

Applications can be started on any hosting-computer, including computers without OpenCL devices. Supports SuperCL, an extension of OpenCL that allows micro-programs to run efficiently on devices of remote nodes. Runs on Linux clusters, with or without MOSIX.

The VirtualCL (VCL) cluster platform is a wrapper for OpenCL™ that can transparently run almost all unmodified OpenCL applications on a cluster with multiple OpenCL devices, as if all the devices are on the local computer. Most OpenCL applications can utilize only devices in the local (hosting) computer. VCL overcomes this limitation by allowing such application to transparently run on cluster-wide devices.

VCL allows all OpenCL devices (CPUs, GPUs, Accelerators) from all vendors, so long as an appropriate OpenCL SDK is installed. VCL is an independent package that runs on Linux clusters, with or without MOSIX. The latest VCL release is independent of MOSIX and it does not interact with MOSIX.

Is there a limit on the number of OpenCL devices that a program can use NO