Subject: Re: UP N:1 vs. MP/UP 1:1 vs. MP/UP M:N and newlock2
To: None <>
From: Bucky Katz <>
List: tech-kern
Date: 02/21/2007 13:55:29
"Greg A. Woods" <> writes:

> So, what you are really asking for is N:1 threading, _not_ M:N,
> especially since you're really only talking about uniprocessor kernels
> here too.

Actually, I'm asking for M:N where N ~= 2. But I'd settle for working
N:1 as I can fake the rest.

> There is, as I understand it (and I may be mistaken), a huge difference.

There can be, yes.  But one day I'll want to do this on an MP...

> I suppose the question to be answered before newlock2 hits a release
> branch is whether or not the specific case of having a special UP
> N:1 libpthread implementation is useful and beneficial enough to
> forgo trying to get the more general case of a MP/UP M:N libpthread
> working with newlock2, or not.

That's certainly one question that should be answered.

Another is whether or not an M:N libpthread can be done with less
kernel intrusion than the SA design.