Ryzen public erratas

[Konstantin Belousov]

On Thu, Jun 14, 2018 at 10:24:17AM -0400, Mike Tancsa wrote:
> On 6/14/2018 9:36 AM, Eric van Gyzen wrote:
> > On 06/13/2018 05:35, Konstantin Belousov wrote:
> >> Today I noted that AMD published the public errata document for Ryzens,
> >> https://developer.amd.com/wp-content/resources/55449_1.12.pdf
> >>
> >> Some of the issues listed there looks quite relevant to the potential
> >> hangs that some people still experience with the machines.  I wrote
> >> a script which should apply the recommended workarounds to the erratas
> >> that I find interesting.
> >>
> >> To run it, kldload cpuctl, then apply the latest firmware update to your
> >> CPU, then run the following shell script.  Comments indicate the errata
> >> number for the workarounds.
> >>
> >> Please report the results.  If the script helps, I will code the kernel
> >> change to apply the workarounds.
> > Kostik:  This thread on the -stable list has a lot of positive feedback:
> > 
> > https://lists.freebsd.org/pipermail/freebsd-stable/2018-June/089110.html
> 
> I have a couple of Epyc boxes that showed the same lockup behaviour. I
> will re-install FreeBSD on them and see if their microcode updates fix
> this issue as well...
I am not sure about only microcode update.  Depending on the BIOS
vendor and current BIOS, you may need all three: BIOS update, microcode
update using cpucontrol/devcpu-data, and running the script I posted.
In the best case, some of this is just redundand.

> 
> Should I run the same cpuctl commands on those CPUs ?  BTW, I am happy
> to loan one out to you in the FreeBSD netperf cluster for a few weeks
> 
> 	---Mike
> 
> 
> 
> -- 
> -------------------
> Mike Tancsa, tel +1 519 651 3400 x203
> Sentex Communications, mike at sentex.net
> Providing Internet services since 1994 www.sentex.net
> Cambridge, Ontario Canada