Intel HFI To Premiere In Linux 5.18 For Improving Hybrid CPU Performance/Efficiency

[phoronix]

Phoronix: Intel HFI To Premiere In Linux 5.18 For Improving Hybrid CPU Performance/Efficiency

The Linux 5.18 kernel this spring is adding support for the Intel Hardware Feedback Interface (HFI, also talked about sometimes as the Enhanced Hardware Feedback interface - EHFI)...

https://www.phoronix.com/scan.php?page=news_item&px=Intel-HFI-For-Linux-5.18

[tildearrow]

Linux always gets the most boring names...

I know it doesn't matter, but seriously to the average consumer it doesn't sound cool.

"Hardware Feedback Interface" or "Thread Director"?

[mlau]

"Hardware Feedback Interface"

That's what Intel calls it in the official Documentation.

[birdie]

And this is still not enough to properly support ADL under Linux. You need some kind of daemon which will instruct the kernel to assign certain tasks to certain cores. And even that is not enough because depending on the workload certain tasks must be moved from P to E cores.

In Windows the kernel and UI are very closely related and work in tandem, so such a feature works seamlessly. In Linux? Have fun. Maybe in a year or two Linux will support ADL properly.

[smitty3268]

Linux always gets the most boring names...

I know it doesn't matter, but seriously to the average consumer it doesn't sound cool.

"Hardware Feedback Interface" or "Thread Director"?

The "average consumer" has zero reason to be digging around linux kernel internals or looking into codenames of hardware features.

Seriously, that's dumb. If you can't appreciate something unless it's got 5 X's in the name, you should probably switch to following a marketing driven project rather than one that cares about actual good engineering.

[smitty3268]

And this is still not enough to properly support ADL under Linux. You need some kind of daemon which will instruct the kernel to assign certain tasks to certain cores. And even that is not enough because depending on the workload certain tasks must be moved from P to E cores.

That seems fairly trivial though, once the hardware capabilities are exposed. I'm not sure why it would be difficult, anyway.

[tildearrow]

And this is still not enough to properly support ADL under Linux. You need some kind of daemon which will instruct the kernel to assign certain tasks to certain cores. And even that is not enough because depending on the workload certain tasks must be moved from P to E cores.

In Windows the kernel and UI are very closely related and work in tandem, so such a feature works seamlessly. In Linux? Have fun. Maybe in a year or two Linux will support ADL properly.

I wonder why couldn't that daemon run in kernel space in the kernel thread just like how RCU or idle_inject run there. A daemon in userspace would be unoptimal.

Windows is a graphical operating system down to the core, so it performs well on desktop (but has some struggle on servers).
Linux is a general-purpose operating system, so it performs well on servers but maybe not so well on desktop.

[middy]

And this is still not enough to properly support ADL under Linux. You need some kind of daemon which will instruct the kernel to assign certain tasks to certain cores. And even that is not enough because depending on the workload certain tasks must be moved from P to E cores.

In Windows the kernel and UI are very closely related and work in tandem, so such a feature works seamlessly. In Linux? Have fun. Maybe in a year or two Linux will support ADL properly.

How is the kernel and UI closely related that causes it to more efficiently scheduler better? Could you elaborate more?

[flower]

And this is still not enough to properly support ADL under Linux. You need some kind of daemon which will instruct the kernel to assign certain tasks to certain cores. And even that is not enough because depending on the workload certain tasks must be moved from P to E cores.

In Windows the kernel and UI are very closely related and work in tandem, so such a feature works seamlessly. In Linux? Have fun. Maybe in a year or two Linux will support ADL properly.

AFAIK the latest PopOS has a userspace damon which does what you describe. works only with gnome though. and atm is quite dumb and only sets process niceness to ui foreground processes

[F.Ultra]

How is the kernel and UI closely related that causes it to more efficiently scheduler better? Could you elaborate more?

What he means is that under Windows the active window/task is given higher priority in the scheduler, the kernel can not do that on its own since it does not know what a window is, and less so which one is in focus.