Checkpoint/Restore Of Unprivileged Processes Sent In For Linux 5.9

[starshipeleven]

Well. not sure if it his reason but in latin america and poor side of asia is quite common for organized crime to buy/steal user data (specially facebook/instagram/gmail) to do all kind of bad stuff from locating people from instagram posts for kidnaps all the way to use your mail accounts to run scams and blackmail, etc.

That's neat, US cops do that too for "identifying suspects".

[starshipeleven]

Oh, it's already there from a long time and it's running on huge systems like 896 cores, 1792 threads and 24,576 GB in a single image, scale-up configuration:

https://www.sap.com/dmc/exp/2018-ben...1-3f6185216861

There's support for 4096 CPUs in a single kernel image for a reason. This is not gearing up, but going for domination.

bigass systems like that are just HPC. High reliability is a different beast. They may use big systems or relatively smaller ones, but it's the OS features that matter. IBM mainframes (Z-systems?) are in this category.

[starshipeleven]

Unfortunately this project is pretty limited ATM, because it's not able to save/restore any application that happens to use graphics. Making that work as I understand would require quite complicated work on the graphics drivers, so I doubt it ever gonna change.

Does this apply to applications that use it for 2D only too (desktop applications, not games)?

[Hi-Angel]

Does this apply to applications that use it for 2D only too (desktop applications, not games)?

Yes. When an application uses graphics in any way, state of the GPU becomes something that needs to be checkpointed. So you need to ask the GPU kernel driver for this state, and there's currently no way to do that.

[starshipeleven]

Yes. When you use graphics in any way, state of the GPU becomes something that needs to be checkpointed. So you need to ask the GPU kernel driver for this state, and there's currently no way to do that.

So it's a server-only feature for now, I'm not surprised, just disappointed.

[Hi-Angel]

Just in case, edited my post to make sentence less vague, to avoid possible confusion: replaced "you" with "an application".

[starshipeleven]

Just in case, edited my post to make sentence less vague, to avoid possible confusion: replaced "you" with "an application".

Ah ok, I identify as an application so I understood what you meant already.

[Vistaus]

That's neat, US cops do that too for "identifying suspects".

Same goes for Dutch and Israeli cops.

[Weasel]

So it's a server-only feature for now, I'm not surprised, just disappointed.

I'm more concerned about how this feature even works in the first place.

There's a blog post about Windows from a MS employee that outlines the issues with such a feature: https://devblogs.microsoft.com/oldne...20-00/?p=39723

(no, they are not Windows-specific)

I'm assuming a checkpointed app will not keep files open, so disaster is waiting to happen. BTW, it's the same with X11 (or Wayland) since they are servers. A checkpointed app will lose the connection to the X server, how do you expect to restore that?

In fact how does this feature even work currently at all without issues?!? I'd love to see how they tackled this problem that Windows couldn't.

[starshipeleven]

I'm assuming a checkpointed app will not keep files open, so disaster is waiting to happen.

you can write to files and delete them even if they are open by another program on Linux, so applications must be able to deal with that already. This is a windows-only issue you windows fanboi.

BTW, it's the same with X11 (or Wayland) since they are servers. A checkpointed app will lose the connection to the X server, how do you expect to restore that?

If you are freezing the display server, all applications under it must be frozen as well. If you are freezing a single application you just need to make a placeholder for its window and stuff for the server.

It's not particularly difficult, it's just glue code. The hard part is saving or restoring GPU state in a sane manner.

In fact how does this feature even work currently at all without issues?!?

It does not work for GUI applications, and that's the only real hard part as I said.