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Re: revivesa status 2008/07/09

On Sat, Jul 12, 2008 at 11:41:43AM +0100, Mindaugas Rasiukevicius wrote:
> Thor Lancelot Simon <> wrote:
> Perhaps you can give us a link to that benchmark which would show how SA
> performs better than 1:1? There were many benchmarks which proven 1:1
> performance, but unfortunately I have not seen any benchmark where SA
> performs better than 1:1 on NetBSD.


Would you really rip out 1:1 threading if someone handed you said 
benchmark? I doubt it, and if you were about to I'd try to talk you out of 

Benchmarking is great for selecting ONE solution. But I'm unaware of 
anyone suggesting _replacing_ 1:1 threading with SA. The suggestion is to 
have both.

Actually, the suggestion is to restore the level of system call backwards 
compatability that we have had with most every other system call since 
NetBSD 1.0.

> It is easy to say "well-understood", "obvious", "saw". But perhaps we can
> be more constructive by providing numbers, test-applications, or something
> like that?

But to what end? The only thing that I can see that would benefit would
either be a discussion about if we should remove 1:1 threading in favor of
SA (a discussion no one is having) or a discussion as to which one should
be the default threading. Given that ad is kicking butt with his
benchmarks that are using our 1:1 threading, I see no reason to not ship
the OS so that, out of the box, it reproduces hist test cases reasonably

The question is should we restore support for system calls we supported in 
NetBSD 4.0 and NetBSD 3.0. We removed support because, well, because the 
code needed more love than we had people interested in giving it. That was 
the right thing to do.

The question now is NetBSD better off merging the revived code in or not.

Take care,


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