Re: Is the netBSD kernel Preemptible ?
David Laight <[email protected]>
| Newsgroups | gmane.os.netbsd.devel.smp |
|---|---|
| Message-ID | <[email protected]> |
On Thu, Jun 13, 2002 at 08:41:15PM -0700, Matt Thomas wrote: > At 04:34 PM 6/13/2002, David Francheski wrote: > >Can anybody tell me if the netBSD kernel itself is preemptible? > >By this I mean can a context-switch to a higher priority process > >occur while in kernel mode? > > The kernel is not currently preemptible. However once the SMP changes are incorporated any code that doesn't have a lock held has to be written as though it could be preempted (because what the other cpu can do is worse). The SVR4 kernel was changed to allow preemption in the kernel at the same time as it was made SMP. David -- David Laight: [email protected]