The following snapshot: 

https://plus.google.com/u/0/photos/albums/pb1i9362aaimkicl8vnkj73kqse5emg7t?pid=6558540565520113042&oid=102927517975380147705

taken from this dashboard:

https://dashboards.corp.google.com/google::analysis_uma_chromeos_wide_profiling_plx_comparative_analytics_dashboard?p=channel:stable&p=triggers:%22PERIODIC_COLLECTION%22&p=numerator:board%3D%27minnie%27&p=percent:0&p=denominator:board%3D%27speedy%27&p=duration:200&p=subfraction:dso%20LIKE%20%27%25kernel.kallsyms%25%27&p=end_date:20180520

shows the ration of time spent in the kernel for minnie (kernel AFDO enabled on R63 - 10032.x.0) vs. speedy (kernel AFDO enabled on R65 - 10323.x.0)

one can see that when we enabled AFDO on Minie 10032.x, the performance degraded. Further one can see that the peformance on speedy degraded on 10323.

The AFDO profiles for these ARM boards are taken from X86 boards running kernel 3.14. It seems in this case, using an x86 profile for an ARM board is not a good idea. 

We will need to investigate this further but, for now, we are going to  disable AFDO on the veyron family.