machdep.hlt_cpus not safe with ULE?

Steven Hartland killing at
Sat Feb 19 12:46:56 UTC 2011

I'm trying to debug a possibly failing CPU, so I thought it would
be easy just disable the cores using machdep.hlt_cpus and see if
we see the panic's we've been seeing.

The problem is it seems ULE doesnt properly support machdep.hlt_cpus
and still schedules processes onto the halted cpus which obviously
causes problems.

Can anyone confirm this behaviour? Should machdep.hlt_cpus and I assume
the logical counterpart never be used with ULE?


This e.mail is private and confidential between Multiplay (UK) Ltd. and the person or entity to whom it is addressed. In the event of misdirection, the recipient is prohibited from using, copying, printing or otherwise disseminating it or any information contained in it. 

In the event of misdirection, illegible or incomplete transmission please telephone +44 845 868 1337
or return the E.mail to postmaster at

More information about the freebsd-stable mailing list