Re: mmap() versus read()

Victor Yodaiken (yodaiken@chelm.cs.nmt.edu)
Tue, 10 Mar 1998 18:27:39 -0700


On Mon, Mar 09, 1998 at 01:46:14PM -0800, Perry Harrington wrote:
> 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.

I've always been unable to understand the utility of kernel threads:
perhaps you can explain it.

> 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

Rob Pike pointed out that the solution to slow process creation is
faster process creation, not another kernel abstraction.

---------------------------------
Victor Yodaiken
Department of Computer Science
New Mexico Institute of Mining and Technology
Socorro NM 87801
Homepage http://www.cs.nmt.edu/~yodaiken
PowerPC Linux page http://www.cs.nmt.edu/~linuxppc
Real-Time Page http://luz.cs.nmt.edu/~rtlinux

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu