[rescue] sparc register windows and context switching...

[Greg A. Woods]

[ On Tuesday, February 5, 2002 at 19:24:11 (EST), dave at cca.org wrote: ]
> Subject: Re: [rescue] SS10/20 death
>
> That's good to hear. I thought the extra work of spilling to the stack
> and especially the added complexity of context switches might negate
> the wins, at least for general unix/c codes. It kind of looks more like
> a custom OS embedded app type design.

I seem to remember Rob Pike saying at an early Plan-9 Usenix BoF that in
general the sparc was faster at context switches than some other
machines available when they first started work on the system (in answer
to a question that as I remember it was something like:  why are the
sparcstations so well supported and other more common machines like PCs
so poorly supported?).

It would be interesting to use something like hbench to try and measure
actual context switching times in real OS & compiler implementations on
several comparable systems with different CPUs and then try to use the
SPEC or similar pure single-task CPU benchmarks to weigh the results and
make them more useful for comparison purposes.

-- 
								Greg A. Woods

+1 416 218-0098;  <gwoods at acm.org>;  <g.a.woods at ieee.org>;  <woods at robohack.ca>
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