Subject: Re: rough SA patch (works on SMP)
To: Nathan J. Williams <nathanw@wasabisystems.com>
From: Greywolf <greywolf@starwolf.com>
List: tech-kern
Date: 06/23/2003 23:02:58
Thus spake Nathan J. Williams ("NJW> ") sometime Today...
NJW> Frank van der Linden <fvdl@netbsd.org> writes:
NJW>
NJW> > On Mon, Jun 23, 2003 at 04:50:32AM -0400, Stephan Uphoff wrote:
NJW> > > FYI: The patch only allows a single SA LWP to be active in
NJW> > > userspace.
NJW> >
NJW> > I assume you mean for an SMP configuration? I believe that restriction
NJW> > has always been there (so far).
NJW>
NJW> For UP, it's not a restriction, it's a deliberate property of SAs. In
NJW> general, the number of SA LWPs in userspace should always be less than
NJW> or equal to the number of CPUs in the system.
??
Do you mean "active SA LWPs"?
Otherwise, wouldn't the restriction mean that sa_create (or whatever
it's called) would automatically fail, and SA LWP would be completely
useless...?
I'm sorry if I'm pointing out the bloody obvious, or if I'm
misunderstanding completely...
NJW> - Nathan
Oh, can I also surmise -- on a slightly different tangent -- that the
primary use thus far for SA/LWP is more or less for function-while-
display (under X, for example (i.e. XMMS/mozilla), so that stuff can just
run in the background without the overhead of fork()/IPC?
[I think I can see the benefit of that, actually. Trying to jump through
the hoops of fork()/IPC for something like a browser would be REALLY
messy.]
Opinion survey: Would dump(8) benefit from SA/LWP?
--*greywolf;
--
SA: I have *no* idea.