Linux Kernel Set To Finally Retire AMD 3DNow!

[phoronix]

Phoronix: Linux Kernel Set To Finally Retire AMD 3DNow!

Queued up as part of the x86/core changes intended for the Linux 5.17 cycle is dropping of the AMD 3DNow! code within the kernel. While 3DNow! brings back fond memories from the days of AMD's K6 and early Athlon processors, AMD deprecated the instructions a decade ago and no longer found in newer processors. Removing of the 3DNow! kernel code is being done as part of some code improvements...

https://www.phoronix.com/scan.php?page=news_item&px=Linux-Kernel-Drop-AMD-3DNow

[willmore]

So we add features with hundreds of KLOC, but we remove a small chunk of well tested code because...progress?

At least they didn't remove support for these processors entirely.

[ResponseWriter]

"up until Bulldozer"

So this would affect a Phenom II and a Llano APU I'm currently running as a NAS/home server, although I guess supporting up to SSE4a more than makes up for it.

[mlau]

It just drop usage of 3Dnow inside the kernel (i.e. fast memcopy).

[Anux]

"up until Bulldozer"

So this would affect a Phenom II and a Llano APU I'm currently running as a NAS/home server, although I guess supporting up to SSE4a more than makes up for it.

It will only effevt CPUs that don't have SSE, some over 20 years old Athlons and even then the impact should be barely noticeable.

[skeevy420]

3DLater!

[NateHubbard]

It will only effevt CPUs that don't have SSE, some over 20 years old Athlons and even then the impact should be barely noticeable.

If you're running one of those processors today, then this probably isn't the bottleneck you're seeing with performance.

[Anux]

If you're running one of those processors today, then this probably isn't the bottleneck you're seeing with performance.

That's for sure. And I was thinking that every 3DNow CPU has MMX so probably even less of an impact when looking at memcpy where no FP is needed.

Most Distros these days only have 64 Bit releases and those with 32 Bit most likely depend an SSE2 or at least some applications do.
Edit: and PAE

[TemplarGR]

"up until Bulldozer"

So this would affect a Phenom II and a Llano APU I'm currently running as a NAS/home server, although I guess supporting up to SSE4a more than makes up for it.

Do you need 3DNow? Does anything use it, really?

[s_j_newbury]

It just drop usage of 3Dnow inside the kernel (i.e. fast memcopy).

I have to admit I was concerned reading the headline since I have machines still in use with 3dnow! (build-time) enabled in userspace: Phenom2 and Athlon X2.

The Phenom2 system is my router/NAS and it has no need of replacement. Performance and power efficiency is more than sufficient for the tasks it performs.