Re: mmap() versus read()

Perry Harrington (pedward@sun4.apsoft.com)
Mon, 9 Mar 1998 13:46:14 -0800 (PST)

>
>
> On Mon, 9 Mar 1998, Perry Harrington wrote:
>
> > I think everyone will
> > agree that the current clone() method of creating threads is costly
> > at best. [...]
>
> uhm, ~20 usecs on a 200 MHz PPro, is that 'costly at best'?

I still count in clock ticks. 35000 something IIRC last time I knew
for a fork()/clone(). Context switches are somewhat costly from what I've
heard too. FWIW, I have a P233MMX now, upgraded from a 486-120, the
cxtx switch on an x86 is much faster than other machines (from what I've
seen), probably from the TSS and builtin intel hacks. What and where are
you getting ~20usec? Anything will be fast on a 200mhz PPro, doesn't mean
that your 486-66 is going to rip Win95 a new ***hole.

>
> -- mingo
>

Pardon me if I seem a little confrontational, I'm not the only one who
sees clone() as costly. Also, compare these to Solaris thread creation
and such, you'll find that solaris can do some pretty good stuff on a
lowly machine. (Perish the thought!)

--Perry

-- 
Perry Harrington       Linux rules all OSes.    APSoft      ()
email: perry@apsoft.com 			Think Blue. /\


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