AMD Confirms Linux Performance Marginality Problem Affecting Some, Doesn't Affect Epyc / TR

[PuckPoltergeist]

2 - uOP Cache
The kernel detects (and sometimes corrects) errors in the uOP Cache.

The kernel doesn't know about a uOP Cache. The kernel knows x86 instructions and MCE reports, the hardware does. Nothing else.

[kimixa]

As someone who suffers from this issue, does this mean the solution is to speak to AMD to get my ryzen replaced?

[Michael]

a

As someone who suffers from this issue, does this mean the solution is to speak to AMD to get my ryzen replaced?

Contact AMD Customer Care as linked to from the article.

[GreatEmerald]

heh, I think you guys need to resize how small of a subset you are. Linux/BSD users that are compiling their systems from scratch that also own ryzens.. what 0.001% of the computer industry or less?

Yeah no, as pointed out, processors with a whole lot of threads are most interesting for developers (and build farms), a lot of whom are running Linux; and compiling code is probably the most common workload for developers (and build farms). Regular users should be pretty fine with quad-cores still, and are thus not running Ryzen.

[k1e0x]

As someone who suffers from this issue, does this mean the solution is to speak to AMD to get my ryzen replaced?

I'ma hold out for a possible microcode fix. I like this chip too much to RMA it right now. lol we'll just have to see what happens.

[polarathene]

It seriously pisses me off that it took Phoronix articles for AMD to realize they needed to look into this. I don't care if they claim they've done it. Too little, too late. What happens next time there is a problem? AMD will ignore their customers unless they feel pressured enough to fix the problems.

Maybe Michael could do a decent QEMU/KVM benchmark to point out awareness on the poor NPT support with AMD. From what I understand it's a bug in QEMU/KVM code that only affects AMD processors. Bit of a recurrent problem/warning to users in the community like r/VFIO, and presumably any companies that build servers that are virtualized to lease to customers(eg Vultr, Digital Ocean).

[RyzenNewbie]

The hardware defect is not related to compilation. It just happens that the problem is most easily reproduced with compilation, since it stresses the right parts of the core. This is why these chips have no problem with Prime95 or Cinebench, the FPUs and ALUs just work fine. And who does a lot of heavy compilation? Linux developers, especially Gentoo users.

that sounds interesting - do you have any ideas for other workloads that act like compilation orgies that could exhibit this issue? For instance, transcode a same video ten times in ten different output files and then bit-compare these output files?

Something like that?

[duby229]

Yeah no, as pointed out, processors with a whole lot of threads are most interesting for developers (and build farms), a lot of whom are running Linux; and compiling code is probably the most common workload for developers (and build farms). Regular users should be pretty fine with quad-cores still, and are thus not running Ryzen.

With the exception of most Gentoo users, though admittedly a small percentage.

[Green]

By the statement of "isolated to these early Ryzen processors", is AMD referring to all of the consumer released Ryzen batches or just a fraction/series of them?

[M46m4]

OK if this happens i want all my premium paid money back... because I only spend my rare money on phoronix.com because it is one of the last community driven websites with "Open"-"Communications" against yes yes yes: the Corporatism/Fascist Monopole/Duopoly evil companies.

then [email protected] has to choose between being the best darling of the "Corporatism/Fascist Monopole/Duopoly evil companies."
or he is true loyal to the community.

Do you really think michael should contact AMD for some problem you have? You should just reach them directly like an amd customer, after all he doesn't work under amd