Re: idle task running on the wrong CPU

From: Kris Kennaway <kris_at_obsecurity.org> Date: Wed, 23 Nov 2005 04:07:07 -0500 · This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:38:48 UTC

On Wed, Nov 23, 2005 at 04:03:34AM -0500, Kris Kennaway wrote:
> On 6.0-STABLE:
> 
>   PID USERNAME  THR PRI NICE   SIZE    RES STATE  C   TIME   WCPU COMMAND
>    13 root        1 171   52     0K     8K CPU1   0   0:00 100.00% idle: cpu1
>  
> Note: the cpu1 idle task is running on CPU 0.  Actually it is not
> running, since it's not accumulating any CPU time, and in fact nothing
> at all is being scheduled on CPU 1.
> 
> Kris

It was pointed out that machdep.hyperthreading_allowed=1 fixes this
bug (it was set to 0).  However, hyperthreading was already in use
(partly), because this machine has 2 physical CPUs with HTT, and CPUs
0, 2 and 3 were running jobs.

Looks like machdep.hyperthreading_allowed=0 does not work as intended.

Kris