Kernel threads inherit CPU affinity from random sibling

[Ryan Stone]

On Fri, Jan 27, 2012 at 10:41 PM, Attilio Rao <attilio at freebsd.org> wrote:
> I think what you found out is very sensitive.
> However, the patch is not correct as you cannot call
> cpuset_setthread() with thread_lock held.

Whoops!  I actually discovered that for myself and had already fixed
it, but apparently I included an old version of the patch in the
email.

> Hence this is my fix:
> http://www.freebsd.org/~attilio/cpuset_root.patch

Oh, I do like this better.  I tried something similar myself but
abandoned it because I misread how sched_affinity() was implemented by
4BSD(I had gotten the impression that once TSF_AFFINITY is set it
could never be cleared).