lkml.org 
[lkml]   [2007]   [Apr]   [7]   [last100]   RSS Feed
Views: [more markup]  [less markup]  [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: CPU offline but power consumption increased?
FromAndi Kleen <>
Date08 Apr 2007 01:38:14 +0200
"Andika Triwidada" <andika@gmail.com> writes:

[cc linux-acpi]

> Question: is that normal? I thought power consumption will be
> automatically reduced if one core offlined.

The current cpu offline essentially just runs a special idle loop.
The standard idle loop is even a bit more aggressive on some systems
because it knows about the deeper ACPI sleep modi.

There are also dependencies between cores because current CPUs
have shared power planes between cores.

I suppose in the future when a whole socket goes off line one could
implement special code to turn off the CPU further. But it likely
won't work on older hardware.

-Andi
-
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: 2007-04-07 22:43    [from the cache]
©2003-2008