Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!bloom-beacon!tut.cis.ohio-state.edu!mailrus!ames!amdahl!pacbell!ditka!qiclab!sopwith!snoopy
From: snoopy@sopwith.UUCP (Snoopy)
Newsgroups: comp.unix.wizards
Subject: overhead of namei (was: ... would you want in the GNU OS?)
Keywords: GNU OS features kernel fun!
Message-ID: <201@sopwith.UUCP>
Date: 3 Jun 89 17:53:08 GMT
References: <106326@sun.Eng.Sun.COM> <395@amc-gw.UUCP> <5021@stiatl.UUCP> <400@amc-gw.UUCP>
Reply-To: snoopy@sopwith.UUCP (Snoopy)
Organization: The Daisy Hill Puppy Farm
Lines: 24

In article <400@amc-gw.UUCP> jhall@emu.UUCP (John Hall) writes:

|  I would be willing to take a performance hit in namei(), if this idea
|  was well implemented.  Think of the incredible functionality it would
|  provide!  In any case, namei() is used only when opening "files" and
|  slightly lower performance here would not affect system performance
|  much at all.

"With the addition of the two caches, the percentage of system time
devoted to name translation dropped from 25 percent to less than 10
percent."

	_The Design and Implementation of the 4.3BSD UNIX Operating System_
		by Leffler, McKusick, Karels, and Quarterman

It appears that namei() soaks up more cycles than one might expect.

    _____     						  .-----.
   /_____\    Snoopy					./  RIP	 \.
  /_______\   qiclab!sopwith!snoopy			|  	  |
    |___|     parsely!sopwith!snoopy			| tekecs  |
    |___|     sun!nosun!illian!sopwith!snoopy		|_________|

		"I *am* the next man!"  -Indy