Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!genrad!decvax!hplabs!felix!fritz!marty
From: marty@fritz.UUCP (Marty McFadden)
Newsgroups: net.unix-wizards
Subject: Re: busy looping in kernel, time question
Message-ID: <698@fritz.UUCP>
Date: Wed, 23-Apr-86 13:28:13 EST
Article-I.D.: fritz.698
Posted: Wed Apr 23 13:28:13 1986
Date-Received: Sat, 26-Apr-86 03:15:47 EST
References: <234@Shasta.ARPA> <14809@onfcanim.UUCP> <291@copper.UUCP>
Reply-To: marty@fritz.UUCP (Marty McFadden)
Organization: FileNet Corp., Costa Mesa, CA
Lines: 23

In article <291@copper.UUCP> stevesu@copper.UUCP (Steve Summit) writes:
>In article <234@Shasta.ARPA> alex@lancelot writes:
>>
>>	Assume I want to busy loop in the kernel for 100 milliseconds, how
>>many times (approx) should I go around a loop which increments an int?
>
>	while(ryaddr->ryics & RY_TR) == 0);

My advice is to be careful here!! The first question about how many times
should one loop is NOT processor portable!! Say for instance, you decide to
upgrade from a 68000 to a 68020 with cache. These 100 millisecond loops are
no longer 100 milliseconds but can virtually take almost NO time at all :-)

The second suggestion is okay, but I suggest that you also add some sort of
timeout mechanism that comes along every few seconds or so and makes sure
that you are not hung in that state.

cheers.
-- 
	Martin J. McFadden
	{decvax, ucbvax}trwrb!felix!marty
	FileNet Corp. 
	Costa Mesa, Ca.