Re: CVS commit: src/sys

[Jukka Ruohonen <jruohonen%iki.fi@localhost>]

On Mon, Feb 28, 2011 at 04:48:43PM +0000, Mindaugas Rasiukevicius 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.

- Jukka.