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From: guy@rlgvax.UUCP (Guy Harris)
Newsgroups: net.unix-wizards
Subject: Re: nice(1) takes an absolute priority a
Message-ID: <293@rlgvax.UUCP>
Date: Tue, 11-Dec-84 18:15:41 EST
Article-I.D.: rlgvax.293
Posted: Tue Dec 11 18:15:41 1984
Date-Received: Sat, 15-Dec-84 00:12:13 EST
References: <243@utcs.UUCP> <47500003@ccvaxa.UUCP>
Organization: CCI Office Systems Group, Reston, VA
Lines: 33

> >	My fix was to use nice(3c) instead of the overkill of getpriority(2).
> >	Diffs follow:
> -------------
> Shouldn't we really be trying to avoid calls to compatibility routines?
> Just because Berkeley didn't bother to remove all their own uses of them,
> shouldn't we try not to introduce any more?  Well, I try, anyway.

If you're writing a program which should run under V7, and 4.1, and S3, and
S5, and... you should use the compatibility routines.

> In what sense is using getpriority "overkill"?  You must mean that using
> it is more work for YOU, since it's noticeably less work for the machine.

Given the number of instructions (kernel and user) executed by using the
"nice" program, I suspect the extra giftwrapping around "setpriority"
provided by the "nice" routine almost completely disappears.  It's hardly
"noticeable".

> If you use nice(3c) you add another call and then do, inside it, the
> getpriority call you could have done yourself.  And whoever reads your
> code has to try to remember whether that old nice call was relative or
> absolute.  If you just used getpriority and setpriority it would at
> least be clear exactly what you were doing.

No argument there.  I *think* all versions of "nice" after V6 add the
value given as an argument to the current "nice", but the V7 manual's
wording (the priority is "augmented" by the argument) is a bit vague
(I checked the 2.9 code, assuming it was basically the same as V7, and
it does work that way); the fact that it is that confusing indicates
that "setpriority" is nicer (no pun intended).

	Guy Harris
	{seismo,ihnp4,allegra}!rlgvax!guy