The mechanism that's in Linux is peer-to-peer direct memory access (P2P DMA). Because of where the money is in Linux, the primary work is for network to storage and storage to storage. Storage to GPU is tricky but in progress. The primary difficulty is making sure that it will work before you try it; I think it currently uses whitelists to achieve that.

The suspend/resume stuff I don't know of anything similar; that's the kind of thing that benefits from a rigidly-defined use-case rather than the usable-for-anything mechanisms that make sense for Linux to prefer. Plus suspend/resume in general has been wrinkly.

RE Quick resume: SIGSTOP / SIGCONT :tongue:

(Kidding of course, I suppose it's something that actually suspends/resumes a process to disk?)

I'm mostly interested in Quick resume though, and yes it seems that it goes to the disk, like the hibernation mode.
On the Xbox Series X, as I understand it (didn't read a lot about it), when "pausing" a game, it doesn't consume resources (RAM, CPU or GPU), if it was the case it would be not great at all for the performances in-game. We speaking about a console of course, it's the only purpose.

How it can be difficult to do that?
Sure Microsoft won't release the source code of the feature, and it will remain Windows exclusive.
But I hope some Linux enthusiasts will work on it for our beloved OS. :wub:

Quoting: CyrilBut I hope some Linux enthusiasts will work on it for our beloved OS. :wub:

The place that kind of functionality would go, should someone make it, would be systemd, as the process that starts and stops other processes.

Quoting: CatKiller

Quoting: CyrilBut I hope some Linux enthusiasts will work on it for our beloved OS. :wub:

The place that kind of functionality would go, should someone make it, would be systemd, as the process that starts and stops other processes.

Have you an opinion on nyrna? I'm curious because from my point of view I don't see the real difficult to have a quick resume feature on Linux (or macOS...) but in the other hand it seems developers might have ones.
On their Github page they mention CRIU, but it doesn't work with X applications...

Skimming through the Nyrna source, it really is just a simple wrapper around SIGSTOP / SIGCONT.

Quoting: CyrilHave you an opinion on nyrna?

I'd not heard of it till you mentioned it. From a quick look, it seems quite simplistic.

I'm curious because from my point of view I don't see the real difficult to have a quick resume feature on Linux (or macOS...) but in the other hand it seems developers might have ones.

For the right implementation of the thing you're after, you'd want something that could keep track of the process and any child processes, and their memory usage, so that all the processes can be suspended together, their RAM contents put into an image which is saved to disc (optionally over restarts) and unloaded, then reloading the RAM image in such a way that the processes don't notice that the actual memory addresses have changed, then restart the processes and recreate their windows without any of them getting confused. It seems like the sort of thing that's doable from systemd/cgroups/some kind of containerisation, as long as there's sufficient interest. Most use cases for that kind of thing would just use a VM, though.

At least Microsoft did it with their console, but as said we don't have the source code and don't know how precisely (even if it's not for Linux though, it could be interesting).

Quoting: CyrilAt least Microsoft did it with their console, but as said we don't have the source code and don't know how precisely (even if it's not for Linux though, it could be interesting).

The Xbox runs each game in a separate Hyper-V VM.

Quoting: CatKiller

Quoting: CyrilAt least Microsoft did it with their console, but as said we don't have the source code and don't know how precisely (even if it's not for Linux though, it could be interesting).

The Xbox runs each game in a separate Hyper-V VM.

So I suppose with that they can achieve it without negative impact on performances. I know nothing about Hyper-V, but it seems it's available on Linux, isn't it?
If yes, anyone have tested it?

On a console, the user don't notice it, it works OOTB. But with a PC, I'm wondering if setup VMs etc worth it... Maybe it can be pretty simple, I don't know.

Quoting: CyrilSo I suppose with that they can achieve it without negative impact on performances. I know nothing about Hyper-V, but it seems it's available on Linux, isn't it?
If yes, anyone have tested it?

Hyper-V is Microsoft's own thing. The Linux equivalent is [KVM](https://en.wikipedia.org/wiki/Kernel-based_Virtual_Machine). Plus other VM solutions like VMWare, VirtualBox, and so on.

On a console, the user don't notice it, it works OOTB. But with a PC, I'm wondering if setup VMs etc worth it... Maybe it can be pretty simple, I don't know.

VMs are very worthwhile for some loads. The scalable computing things like AWS, Azure, and so on use VMs: when you want another instance you fire up another VM image. Plus they're portable, so you can take your VM snapshot to a different machine and just start it up there, since the hypervisor exposes the same interface to the software regardless of the hardware. So you can do resilience stuff and load-balancing stuff pretty readily.

Then you've got containers, like Docker, Kubernetes, snaps, and Valve's Soldier, that provide isolation and sandboxing, but aren't a VM. It's a sliding scale of abstraction.

So it's definitely worthwhile for some people to set it up, but whether it's worthwhile enough to be able to pause a game so that someone gets round to doing that, I couldn't say. It's the kind of thing that Valve could do, for the same reasons as Microsoft do, if they were to release a new version of the Steam Machines, or it's something that Canonical could do to extend their snaps and cloud stuff, or it's something that Google could do to extend Kubernetes and Android stuff, or anyone else with an itch to scratch. If they wanted to, and could find the motivation.