Per core frequency control

Svein Skogen (Listmail account) svein-listmail at
Tue Nov 9 13:17:19 UTC 2010

On 09.11.2010 11:56, David Naylor wrote:
> Hi,
> I was reading through cpufreq(4) and in the bugs section it mentions that per 
> core (or CPU) frequency control is not supported.  That all cores/CPUs have to 
> be at the same speed.  
> What is the reason for that?  
> Is it an infrastructure problem with FreeBSD or has it just not been 
> implemented?  
> And how will the recent work on event timers (and a "tickless" kernel) impact 
> on this problem? 

You did read the "symmetric" part of "symmetric multi processor" didn't you?

It's a limitation of the technology. One clock.


  /"\   |Svein Skogen       | svein at
  \ /   |Solberg Østli 9    | PGP Key:  0xE5E76831
   X    |2020 Skedsmokorset | svein at
  / \   |Norway             | PGP Key:  0xCE96CE13
        |                   | svein at
 ascii  |                   | PGP Key:  0x58CD33B6
 ribbon |System Admin       | svein-listmail at
Campaign|     | PGP Key:  0x22D494A4
        |msn messenger:     | Mobile Phone: +47 907 03 575
        |svein at | RIPE handle:    SS16503-RIPE
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing on usenet and in e-mail?
                     Picture Gallery:


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 260 bytes
Desc: OpenPGP digital signature
Url :

More information about the freebsd-questions mailing list