Subject: Re: DUMMY_NOPS is confusing me.
To: None <port-i386@netbsd.org>
From: Bernd Sieker <bsieker@freenet.de>
List: port-i386
Date: 05/16/2000 19:14:58
On 16.05.00, 11:06:59, Grey Wolf wrote:
> The comment for DUMMY_NOPS in conf/GENERIC is confusing:
> 
> #eliminate delay no-ops in I/O; recommended on all but very old machines
> #options	DUMMY_NOPS
> 
> It is commented out by default in GENERIC.  Should I be uncommenting
> it?

Yes, you should uncomment it. The effect is that in some i/o routines
nops are replaced by a null definition and thus no nops are executed,
which speeds up things a bit.

The explaning text in the kernel config file is a bit confusing, but
still correct.

Enabling DUMMY_NOPS eliminates the nops in i/o, which are only
neccessary on some very old machines.

I was also confused by this until I grepped through the sources
themselves to see what really is done here.

> 
> 				--*greywolf;
> --
> 	OpenSource is NOT exclusive to Linux.  Explore your options!

-- 
Bernd Sieker

NetBSD: Oh my god! They support my hardware! You hackers!
		-- Antti Kantee