Scheduler Changes For Linux 5.15 - Still No Sign Of Any Intel Thread Director Optimizations

[waxhead]

There is one thing I have never understood and that is why processes seem to jump between cores on Linux (and Windows) machines even if there is low load. I don't see any reason for load balancing a task UNLESS all the CPU time is used up. Would it not be better if the task stays on the CPU and new tasks is allocated to the CPU cores with the least amount of load / biggest timeslice budget left.

[uid313]

The Alder Lake CPU is interesting because it has 8 powerful cores and 8 energy efficient cores for a total of 16 cores, so now desktop x86 has more cores than ever and an interesting heterogeneous architecture similar to the ones long used in ARM processors on smartphones.

But rumors is that Alder Lake is very power hungry, that it uses up to 250 W which is rather insane!

[chuckula]

At HotChips, Intel did confirm that Thread Director support is coming to Linux (not a big surprise). However, they did not have a specific timeline on when it would land.

Given that Alder Lake will start first on the gaming desktop segment and eventually work its way into notebooks and lower-end servers with Xeon-enabled silicon, I would guess support will land early in 2022 as Alder Lake goes more mainstream. Of course TD support isn't needed to get Linux to running on the chip, but it should be a nice feature when support is completed.

[phoronix]

Phoronix: Scheduler Changes For Linux 5.15 - Still No Sign Of Any Intel Thread Director Optimizations

Ingo Molnar began sending in his pull requests bright and early as usual for the just-opened Linux 5.15 merge window. With the scheduler changes for this next kernel version there are some improvements worth mentioning but also worth mentioning is what hasn't found its way to the kernel yet: any software optimizations around Intel Thread Director for upcoming Alder Lake processors...

https://www.phoronix.com/scan.php?page=news_item&px=Linux-5.15-Scheduler