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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.ecn.uoknor.edu!news.wildstar.net!serv.hinet.net!news.uoregon.edu!arclight.uoregon.edu!news.mathworks.com!uunet!in1.uu.net!204.191.213.61!ott.istar!istar.net!gateway.qnx.com!not-for-mail From: doug@qnx.com (Doug Santry) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: Where does all my RAM go? Date: 7 Feb 1997 14:32:11 -0500 Organization: QNX Software Systems Lines: 45 Message-ID: <5dfvvr$cq0@qnx.com> References: <5d40te$3l3$1@gail.ripco.com> <32FA40A0.794BDF32@acm.org> NNTP-Posting-Host: qnx.com Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:35210 In article <32FA40A0.794BDF32@acm.org>, Gabor Kincses <gabor@acm.org> wrote: >David Richards wrote: >> >> I have a P133 running 2.1.6 with 48MB installed. All the RAM is available >> after booting, but a couple hours later, it seems to shrink. >> >> 'top' reports the following memory utilization: >> >> Mem: 22M Active, 1056K Inact, 5756K Wired, 15M Cache, 5218K Buf, 948K Free >> Swap: 109M Total, 64K Used, 109M Free >> >> Aside from the numbers not adding up, can anybody explain the meaning of >> the categories, especially 'Wired' and 'Cache' ? >> > >Not so fast: >22 + 1.06 + 5.76 + 15 + 5.22 + .95 = 49.99 MB. >Seems that FreeBSD may have even added a few SIMMS in there. This OS is >better than FREE! ;-) Next time I need more memory I'll just run another instance of top! >See top(1) for a really useful description: > Active: > number of pages active in use. > > Inact: number of pages inactive not in use. > > Wired: number of pages wired down pages that are no elegible for theft. cache is number of cached pages, they hold data that may be needed again soon. The system will use this before stealing pages so they are in effect "free" too. For instance, if you run "ls" a lot, then the first time it will demand page ls into memory. These pages are then cached after use. The next time you run "ls" it doesn't need to go to disk if the pages weren't used. DJS