* Matt Dillon <[EMAIL PROTECTED]> [010415 23:16] wrote:
>                               For example, all this work on a preemptive
>     kernel is just insane.  Our entire kernel is built on the concept of
>     not being preemptable except by interrupts.  We virtually guarentee
>     years of instability and bugs leaking out of the woodwork by trying to
>     make it preemptable, and the performance gain we get for that pain
>     is going to be zilch.  Nada.  Nothing.

Pre-emption is mearly a side effect of a mutex'd kernel.

The actual gains are in terms of parallel execution internally.
Meaning if we happen to copyin() a 4 meg buffer we can allow more
than one process to be completing some sort of work inside the
kernel other than spinning on the giant lock.

Instead of asking why a piece of software is using "1970s technology,"
start asking why software is ignoring 30 years of accumulated wisdom.

To Unsubscribe: send mail to [EMAIL PROTECTED]
with "unsubscribe freebsd-current" in the body of the message

Reply via email to