freebsd stable - Jun 2018 - Ryzen issues on FreeBSD ? (with sort of workaround)

> The compile bug has been fixed for me.  However, last I checked I can
> still freeze a system by generating a lot of network traffic between VMs
> in either bhyve or virtbox.  Its been a while since I tested (couple of
> months) but I dont recall anything obviously committed that highlighted
> that issue.  Note this is on Epyc and Ryzen boxes
Yes, it was your iperf3 tests which enable me to freeze the system with
SMP enabled. With SMP disabled it works fine, however. have you tried
that at all ? The only other settings I ahve are the global C-states
and cool-n-quiet being disabled. I dont really care about either so
havent tested re-enabling them.

-pete.

On 6/3/2018 1:10 PM, Pete French wrote:
> 
>> The compile bug has been fixed for me.? However, last I checked I can
>> still freeze a system by generating a lot of network traffic between
VMs
>> in either bhyve or virtbox.? Its been a while since I tested (couple of
>> months) but I dont recall anything obviously committed that highlighted
>> that issue.? Note this is on Epyc and Ryzen boxes
> 
> Yes, it was your iperf3 tests which enable me to freeze the system with
> SMP enabled. With SMP disabled it works fine, however. have you tried
> that at all ? The only other settings I ahve are the global C-states
> and cool-n-quiet being disabled. I dont really care about either so
> havent tested re-enabling them.
I have c-states disabled on the ryzen both for FreeBSD and Linux.  To
disable SMP on the Epyc doesnt seem to be possible. But then again kill
off 31 cores is a heavy cost to pay for stability :(  When I am back at
the office, I will see if a recent checkout of HEAD still freezes the Epyc.

	---Mike


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Mike Tancsa, tel +1 519 651 3400 x203
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