Re: Hyperthreading in -ac series

From: James Cleverdon (
Date: Fri Sep 20 2002 - 17:47:59 EST

On Friday 20 September 2002 03:36 pm, Guido Arenstedt wrote:
> Hyperthreading does not seem to work in the -ac series
> it works fine with a stock 2.4.19 kernel
> during bootup i only get the message:
> WARNING: No sibling found for CPU 0.
> WARNING: No sibling found for CPU 1.
> or is this done on purpose?

The latter. Hyperthreading _is_ working in the kernel, but it is not finding
"sibling" CPUs to match the real ones. (Or, as we prefer to call them,
DiVitos to match the Schwartzenegers. ;^)

Check your BIOS. Some turn off hyperthreading by default. (Notably, IBM's

James Cleverdon
IBM xSeries Linux Solutions
{jamesclv(Unix, preferred), cleverdj(Notes)} at us dot ibm dot com

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