detecting hyperthreading

[Pokala, Ravi]

-----Original Message-----
From: Freddie Cash <fjwcash at gmail.com>
Date: 2015-03-10, Tuesday at 09:02
To: Ravi Pokala <rpokala at panasas.com>
Cc: "lokadamus at gmx.de" <lokadamus at gmx.de>, Rui Paulo <rpaulo at me.com>,
"freebsd-hackers at freebsd.org" <freebsd-hackers at freebsd.org>
Subject: Re: detecting hyperthreading

>​6 lines or so below the Features line shows the kernel loading "cpu0
>(BSP)", and then "cpu1 (AP/HT)".
>
>Compare that to a system without HTT, where any extra cpus only show
>"(AP)".
>
>It's not perfect, but one could grep through /var/run/dmesg.boot looking
>for "cpu" lines and checking for "(AP)" or "(AP/HT)".​

Yeah. There's tons of info that could be scraped out of dmesg.boot, but
actually doing that - let alone from C - is a pain. :-P

-Ravi
>