News: 0001498318

  ARM Give a man a fire and he's warm for a day, but set fire to him and he's warm for the rest of his life (Terry Pratchett, Jingo)

ARM64 SMT Control Patches Updated For The Linux Kernel

([Arm] 6 Hours Ago Toggling SMT On ARM)


While ARM-based SoCs with Simultaneous Multi-Threading (SMT) aren't too common, there do exist some such as select models of the Huawei Kunpeng server SoC with SMT or there HiSilicon Kirin 9000S. As such Huawei/HiSilicon engineers have been working to expose SMT controls on ARM64 for the Linux kernel.

Similar to Linux x86/x86_64 being able to toggle Simultaneous Multi-Threading support at run-time, the patches that have been worked on by Huawei and Huawei-owned HiSilicon to extend the Linux SMT controls to ARM64 so that the SMT behavior can be manipulated at run-time.

They are extending the run-time SMT controls to ARM64 on the basis of general security vulnerability concerns as well as for better single-thread CPU performance in some workloads and possibly CPU power consumption benefits.

The engineers have tested their ARM64 SMT controls both on real ACPI-based ARM64 server hardware with SMT as well as on ACPI/OF-based QEMU virtual machines.

The [1]v6 patches were posted today as the latest work on this support. The sixth revision to these patches bring various improvements as a result of earlier code review.



[1] https://lore.kernel.org/lkml/20241015021841.35713-1-yangyicong@huawei.com/



phoronix

X windows:
We will dump no core before its time.
One good crash deserves another.
A bad idea whose time has come. And gone.
We make excuses.
It didn't even look good on paper.
You laugh now, but you'll be laughing harder later!
A new concept in abuser interfaces.
How can something get so bad, so quickly?
It could happen to you.
The art of incompetence.
You have nothing to lose but your lunch.
When uselessness just isn't enough.
More than a mere hindrance. It's a whole new barrier!
When you can't afford to be right.
And you thought we couldn't make it worse.

If it works, it isn't X windows.