Re: revivesa status 2008/07/09

[Thor Lancelot Simon <tls%rek.tjls.com@localhost>]

On Mon, Jul 14, 2008 at 11:49:52PM +0300, Aleksey Cheusov wrote:
>  >> In its current form SA threading is a regressive proposition. Even if all
>  >> the remaining issues are addressed, what benefits would it bring over and
>  >> above 1:1 threading?
> 
> >     As I understand it there are two factors in favour of keeping SA:
> 
> >     - There was a report of a significant performance gain on single
> >       core embedded arm32
> >     - If we keep SA for 5.0 it allows people to run a 4.0 userland
> >       on a 5.0 kernel while upgrading (and makes COMPAT_40 useful).
> 
> Does anybody know how well 1:1 threading model is in case of huge
> amount of threads, say, several hundreds or even thousands?  How well
> N:M in such situations (and NetBSD's SA)? Any benchmarks out there?

Yes.