lkml.org 
[lkml]   [2004]   [Oct]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: How is user space notified of CPU speed changes?
From
Date
On Fri, 2004-10-22 at 07:23, Alan Cox wrote:
> On Gwe, 2004-10-22 at 00:01, Lee Revell wrote:
> > This issue came up on the JACK (http://jackit.sf.net) mailing list.
> > Google was not helpful so I ask here.
> >
> > JACK needs to know the CPU speed, in order to calculate the DSP load
> > among other things. It used to be a valid assumption that you could
> > calculate it on startup and it would not change.
>
> No it did not. It has never been a safe assumption. Even my old PC110
> does APM non-linux assisted shifts between 8 16 and 33Mhz. In addition
> there are boxes with dual CPU's and different multipliers - dual
> 300/450's were not uncommon.
>
> And thats before we even mention such things at hyped-threading.

Seems like you are implying that any userspace app that needs to know
the CPU speed is broken. Is this correct?

Lee

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:07    [W:0.231 / U:0.764 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site