Date: Thu, 31 Jan 2002 11:40:39 +0100 From: Erik Trulsson <ertr1013@student.uu.se> To: RJ45 <rj45@slacknet.com> Cc: freebsd-questions@freebsd.org Subject: Re: Memory problem on Dual PIII Message-ID: <20020131104039.GA73719@student.uu.se> In-Reply-To: <Pine.LNX.4.21.0201310320300.25037-100000@slacknet.slacknet.com> References: <Pine.LNX.4.21.0201310320300.25037-100000@slacknet.slacknet.com>
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On Thu, Jan 31, 2002 at 03:25:36AM -0700, RJ45 wrote: > > Hello, > I have a Dual PIII with 1GB RAM. > I have the following problem which I found out using snortsnarf. > This is my actual memory usage: > > Mem: 122M Active, 689M Inact, 120M Wired, 62M Cache, 163M Buf, 514M Free > > If I use a high CPU and Memory bound program like snortsnarf or even dd > with a very large file, the Free Memory starts going down and the Active > Memory start increasing. When the Free Memory reaches 0 and the active > memory is around 600MB snortsarf dies with out of memory message but the > WEIRD thing is that the Inactive memory ALWAYS stays at 689MB and it is > NEVER used like if it does not work... so that I have about half of my > total RAM amount which is NEVER used. > This seeems to be a big problem. > anyone has some hint about it ? > thanks It sounds somewhat weird but my guess at what happens is the following: By default a single process cannot use more than 512MB of data. I guess that that is the limit your process runs up against. Since this is about the size of your Free memory I guess it is just coincidence that this happens at the same time as Free reaches 0. The system tries to use Free memory first and then use Inactive. (Free memory is just that, free and unused. Inactive memory is memory which contains potentially useful data which can be thrown away if necessary.) Try running 2 memory hungry programs at the same time and see what happens. My guess is that the amount of Incactive memory will start to shrink then. (And both programs will die after using about 512 MB each.) (Note: This is just an educated guess at what is going on. It might be something else that is wrong.) -- <Insert your favourite quote here.> Erik Trulsson ertr1013@student.uu.se To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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