From owner-freebsd-current Sun Apr 5 15:23:57 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id PAA29792 for freebsd-current-outgoing; Sun, 5 Apr 1998 15:23:57 -0700 (PDT) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from mail.kersur.net (root@mail.kersur.net [199.79.199.3]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id PAA29783; Sun, 5 Apr 1998 15:23:50 -0700 (PDT) (envelope-from dswartz@druber.com) Received: from manticore (manticore.druber.com [207.180.95.108]) by mail.kersur.net (8.8.8/8.8.8) with SMTP id SAA13523; Sun, 5 Apr 1998 18:24:49 -0400 (EDT) Message-Id: <3.0.5.32.19980405182346.00926c80@mail.kersur.net> X-Sender: druber@mail.kersur.net X-Mailer: QUALCOMM Windows Eudora Light Version 3.0.5 (32) Date: Sun, 05 Apr 1998 18:23:46 -0400 To: dyson@FreeBSD.ORG From: Dan Swartzendruber Subject: Re: swap-leak in 2.2.5 ? Cc: dg@root.com, dag-erli@ifi.uio.no, stable@FreeBSD.ORG, current@FreeBSD.ORG In-Reply-To: <199804052135.QAA00680@dyson.iquest.net> References: <3.0.5.32.19980405172640.00915e30@mail.kersur.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG At 04:35 PM 4/5/98 -0500, John S. Dyson wrote: >Dan Swartzendruber said: >> >> My only quibble with this technique is that it would seem to make it >> harder to tell if your machine is really running low on swap or not >> (e.g. swap as backing store for stack/heap/whatever *is* critical and >> allocation failure can cause application failure, whereas swap being >> used to cache random cruft is in the "who really cares" department). >> Or is there some way to tell the difference? >> >It is difficult not only to tell if you are low on swap, but also it >is hard to quantify being low on memory. I have been thinking about >this over the last year or so. Here's an off-the-cuff idea: since the confusing usage of swap as a caching mechanism is only a performance optimization, how bogus would it be to not report it. Lie. If my workstation has 64MB of swap set up, 8 of which is being used for real backing store, and 12 of which is being used to cache filesystem pages, have swapinfo lie and report only 8MB in use. Possibly add a flag to swapinfo to report both kinds of usage (granted this makes it necessary for track what a given swap block is used for, but...) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message