Re: CVS commit: src/sys

[Mindaugas Rasiukevicius <rmind%netbsd.org@localhost>]

Jukka Ruohonen <jruohonen%iki.fi@localhost> wrote:
> > Why interrupts are disabled here?  Calling xc_wait() with interrupts
> > disabled is, at minimum, very expensive, and I would say it is wrong.
> > Note that xc_wait(9) does not necessary spin - it can block.
> 
> Because interrupts must be disabled when APERF and MPERF are read. See the
> references in the comment, particularly the AMD one.

Why they are not disabled in acpicpu_md_pstate_percent_status(), called on
remote CPU, but around xcall(9) calls, which is potentially broken?

Also, it has no locking.  Is it single-threaded?

-- 
Mindaugas