On Sat, Oct 20, 2001 at 10:42:35PM -0400, Roland McGrath wrote:
> Indeed.  I think the best plan is to scrutinize the pmap locking strategy
> and do something similar.

I am looking into this, but it looks quite hard.  In fact, it requires an
interrupt to signal the other processors (SMP_IPI_VECTOR == 13 is used for
pmap changes).  Is there a free interrupt that can be used?  Can we
piggyback on the pmap interrupt without increasing the cost for it?

I have only a vague idea how the pmap interrupt stuff works, the comments in
i386/intel/pmap.c helped.  However, they also discouraged me a bit from this
complex solution.

Makes me wonder how Linux behaves, I think that I/O bit mangling is task
based here, but as threads are implemented as tasks, I don't think it works
out there the way we want it to behave for us.

I am inclined to postpone this, and just have a simple lock for the other
races and a #warning for SMP machines, that other cpus will only pick it up
after they are rescheduled.

Thanks,
Marcus

-- 
`Rhubarb is no Egyptian god.' Debian http://www.debian.org [EMAIL PROTECTED]
Marcus Brinkmann              GNU    http://www.gnu.org    [EMAIL PROTECTED]
[EMAIL PROTECTED]
http://www.marcus-brinkmann.de

_______________________________________________
Bug-hurd mailing list
[EMAIL PROTECTED]
http://mail.gnu.org/mailman/listinfo/bug-hurd

Reply via email to