After 5 Years, FSGSBASE Support Finally Ready For Linux To Enhance AMD/Intel Performance

[kcrudup]

Well, if you want to get more performance out of your system, go ahead and install the Xanmod kernel. It has enabled FSGSBASE in stable 5.7 and in 5.8 edge.

FSGSBASE been merged into Linus' master now- so if you've got the ability to make Xanmod, you could also try the master branch.

[Azrael5]

Which are the general CPus instructions excluded from kernell currently?

[Vistaus]

this is intel for you they dropped support like intel stock drop every years

It also says that it enhances AMD performance, so did AMD drop the ball as well then?

[FPScholten]

Well, if you want to get more performance out of your system, go ahead and install the Xanmod kernel. It has enabled FSGSBASE in stable 5.7 and in 5.8 edge.
No problems found when using it in Ubuntu.

[Aryma]

after Intel dropped the ball

this is intel for you they dropped support like intel stock drop every years

[sheepdestroyer]

Here are some numbers from last year compared to unmitigated - https://www.phoronix.com/scan.php?pa...fsgsbase&num=2

This is not comparing perf of FSGBASE with AND without mitigations as FireBurn asked. I would be interested in tat too.

[Azrael5]

Excellent improvement!

[CochainComplex]

Would love to see this compared with and without mitigations - i.e. does it speed things up even when mitigations=off is set

https://github.com/xanmod/linux it has the FSGSBASE patch.

use the mitigation=off kernel boot parameter

[Michael]

Would love to see this compared with and without mitigations - i.e. does it speed things up even when mitigations=off is set

Here are some numbers from last year compared to unmitigated - https://www.phoronix.com/scan.php?pa...fsgsbase&num=2

[Peter Fodrek]

What about preliminary Glibc HWCAPS bencmarks for Zen, Zen (called Zen1.5 by myself) and Zen2

https://www.phoronix.com/scan.php?page=news_item&px=glibc-hwcaps-RFC

?
And what about use of similar technologies inside kernel out of arch directory (inside menuconfig rule of kernel makefile is so obsolete)

Maybe some multi-architecture kernel build is to be mentioned. (use of NOP to ensure same virtual address for more architectures and for example use two pagetabeles - one for x86_64, one for ARMv8a for example and after switch to other CPU just set correct table to CR3 for x86 or similar register for ARM)


Maybe soft of "Skybridge 2" (Skybridge with multiple architecture chiplets inside same CPU package)

https://www.electronicdesign.com/technologies/microprocessors/article/21799866/amds-project-skybridge-unifies-x86-and-64bit-arm

may be possible then