RE: RE: [PATCH 1/2] x86/resctrl, Documentation: Keep mbm_assign_mode "default" on boot

[Luck, Tony]

> > 1) Does it start over from zero?
> >     Seems a sane option.
> > 2) Or does the monitor group see whatever the counter was at
> > when being used by some other group?
> >     Seems less sane.
>
> As per this code, it should start over from 0.
>
>   } else if (ret == -EINVAL) {
>                  am = get_arch_mbm_state(hw_dom, rmid, eventid);
>                  if (am)
>                          am->prev_msr = 0;
>          }

Nope. If you want the value reported to the user to start over from zero,
then prev_msr should be set to the current value of the counter. That
would make the next read start from zero.

-Tony