Subject: Re: per-cpu TSS
To: None <port-i386@netbsd.org>
From: YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
List: port-i386
Date: 12/11/2007 20:52:26
[ replying to a mail which i posted in 2003 ]

> hi,
> 
> attached diff is to use per-cpu tss rather than per-process tss.
> number of processes are no longer limited by number of gdt slots with this.
> i tried hbench's lat_ctx benchmark and didn't notice any performance
> differences.  (although it might be differ for processes with i/o bitmaps.)
> any comments?
> 
> todo: kvm86
> 
> YAMAMOTO Takashi

systems are getting larger and the limit is getting relatively smaller.

is there anyone who still believes switch-by-tss is faster?

can anyone explain how switch-by-tss helps mach-like continuation?
(i don't think it helps.)

does anyone want to implement "gdt entry swapping" which mycroft suggested?
although i'm not really sure if i understand what he meant correctly,
it sounds like too much complexity for little gain.

YAMAMOTO Takashi