Xref: utzoo comp.protocols.nfs:1877 comp.arch:21244 Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!lll-winken!elroy.jpl.nasa.gov!sdd.hp.com!uakari.primate.wisc.edu!dali.cs.montana.edu!milton!ns.uoregon.edu!duff.uoregon.edu!jqj From: jqj@duff.uoregon.edu (JQ Johnson) Newsgroups: comp.protocols.nfs,comp.arch Subject: Re: The merits of FCFS for file servers Message-ID: <1991Mar5.223443.21187@ns.uoregon.edu> Date: 5 Mar 91 22:34:43 GMT References: <28975@cs.yale.edu> Sender: news@ns.uoregon.edu Reply-To: jqj@duff.uoregon.edu (JQ Johnson) Organization: University of Oregon Network Services Lines: 19 pcg> The latter argument is somewhat doubtful as there is contradictory pcg> evidence about the relative merits of FCFS and of elevator style pcg> sorting as used by the Unix kernel. lm> Ahem. References, please? Interested readers should see the last TOCS, specifically King, Richard P. (1990) Disk arm movement in anticipation of future requests. _ACM TOCS_ 8, no. 3 (August 1990), pp. 230-250. King argues that sorting is irrelevant since in most practical systems the queue length is seldom more than 1, hence the important thing is to have an algorithm that tends to leave the actuator in a reasonable (read "average" or "near the center" for many distributions of requests) place. -- JQ Johnson Director of Network Services Internet: jqj@oregon.uoregon.edu University of Oregon voice: (503) 346-4394 250E Computing Center BITNET: jqj@oregon Eugene, OR 97403-1212 fax: (503) 346-4397