Linux 4.10 Is Hopefully In Good Shape For AMD Zen / Ryzen Processors

[phoronix]

Phoronix: Linux 4.10 Is Hopefully In Good Shape For AMD Zen / Ryzen Processors

AMD's upcoming Ryzen (Zen) processors appear to be in good enough shape that they are working on the current mainline kernel as far as I can tell based upon limited information available prior to getting my hands on the CPUs or getting any official announcement from AMD, but some Linux kernel patches have yet to be mainlined. The yet-to-be-merged work appears to be more for non-core features and Zen server functionality with those CPUs shipping later than the upcoming Ryzen desktop CPUs...

http://www.phoronix.com/scan.php?page=news_item&px=AMD-Zen-Ryzen17h-Patches

[hxfhjkl]

Will it be possible to backport these to older kernels, or is zen 4.10+ exclusive?

[torsionbar28]

Will it be possible to backport these to older kernels, or is zen 4.10+ exclusive?

I think it's a features thing. You can probably install CentOS 5 or Ubuntu 8.04 or any other old obsolete distro/kernel on Zen. Heck, I've got Windows NT 4.0 running in a VM on an intel Skylake machine. Of course it can't utilize any of the Skylake features, but it does run. That's kind of the point of sticking with the x86 architecture for so long, is backwards compatibility.

I'd bet that Red Hat will back port the Zen code to the 2.6 and 3.10 kernels as used in RHEL 6 and RHEL 7. As big of a deal as Zen is, Red Hat will likely ensure their OS runs out of the box on it, and can be safely pre-installed by Dell, HP, IBM, etc. on new servers. They actively do this for newly released intel chips, so why wouldn't they for Zen? https://access.redhat.com/support/policy/intel

[eydee]

Sounds like a non-issue. The CPUs will still take at least a month or more to arrive. Probably more, 2 or 3 months. By that time 4.10 will be obsolete. Distros sticking to older versions will probably backport code from something that's available then. (5.x?)

[tomtomme]

Sounds like a non-issue. The CPUs will still take at least a month or more to arrive. Probably more, 2 or 3 months. By that time 4.10 will be obsolete. Distros sticking to older versions will probably backport code from something that's available then. (5.x?)

Wrong. 4.10 kernel is released in 2 months.

[Kano]

First of all a new CPUs are usally always backwards compatibe - this ist not the same as with GPUs. If you can not use one of the new security features it does not matter at all. If a CPU requires optimized binaries to run those with a reasonable speed then this CPU hast no chance to be successful. Currently still the main thing to get old code running fast is raw speed/core. Otherwise only selected benchmarks will run fine or when you configure dedicated cores for VMs and run lots of em. Hard to get full load with games and 8 cores. Phenom required special hacks in the kernel to workaround bugs - not good for marketing.

Another thing is the board where you put the CPU. Many new boards only feature USB 3(.1) ports. This means you need a PCI-E card with legacy USB 2.0 ports or a modified install image. Linux is relatively uncritical in this case, Windows 7 and older have got problems. (Intel does not provide USB 3.0 drivers for XP btw.) The same could apply for very new onboard nics - if you require a very old kernel then extra drivers or an older external nic ist required.

[starshipeleven]

Many new boards only feature USB 3(.1) ports. ... Linux is relatively uncritical in this case, Windows 7 and older have got problems. (Intel does not provide USB 3.0 drivers for XP btw.)

who cares of win7 and older anyway? Newer processors are supported only by win10 (some OEM PCs are exempt) http://www.zdnet.com/article/heres-m...ing-windows-7/

Linux "livecds" can boot fine over usb 3.0 since a long while, the rest is about lack of hardware support of the newest stuff unless you run bleeding edge distros, that is well-known on Linux.

[pal666]

Currently still the main thing to get old code running fast is raw speed/core.

Currently still the main thing to get old code running fast is to get it multithreaded. raw speed/core has hit a wall of diminishing returns. just compare progress in cpus vs gpus during last years. gpus are just adding more cores, cpus are just standing still with no progress at all

Hard to get full load with games and 8 cores.

with obsolete games which do multithreading like "sound on one thread, graphics on second thread, logic on third thread". still, you could add multithreading in drivers. like compile shaders in parallel.

Many new boards only feature USB 3(.1) ports.

i've never seen such board. care to show example?

[schmidtbag]

Will it be possible to backport these to older kernels, or is zen 4.10+ exclusive?

The simple way to look at it is Zen will work on older kernels, with caveats. It won't be very optimized but it will work. It's kind of like running an i7 on Windows XP - you can still do it but you're going to miss out on a lot of performance.

[bridgman]

Not 100% sure, but generally the features going into newer kernels are for performance in server environments more than desktop.