From owner-freebsd-questions Mon Aug 25 22:15:53 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id WAA08575 for questions-outgoing; Mon, 25 Aug 1997 22:15:53 -0700 (PDT) Received: from dyson.iquest.net (dyson.iquest.net [198.70.144.127]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id WAA08560 for ; Mon, 25 Aug 1997 22:15:47 -0700 (PDT) Received: (from root@localhost) by dyson.iquest.net (8.8.6/8.8.5) id AAA26372; Tue, 26 Aug 1997 00:15:33 -0500 (EST) From: "John S. Dyson" Message-Id: <199708260515.AAA26372@dyson.iquest.net> Subject: Re: Slowly declining memory In-Reply-To: from Charles Mott at "Aug 25, 97 06:51:13 pm" To: cmott@snake.srv.net (Charles Mott) Date: Tue, 26 Aug 1997 00:15:33 -0500 (EST) Cc: freebsd-questions@FreeBSD.ORG Reply-To: dyson@FreeBSD.ORG X-Mailer: ELM [version 2.4ME+ PL31 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-questions@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk Charles Mott said: > On Mon, 25 Aug 1997, John S. Dyson wrote: > > > > The system is aggressive about caching the filedata and .text+.data, and > > if there isn't other, more important competing need, the system will just > > keep on remembering more and more data. It is not a problem, but simply > > using all of available memory if it can. > > > > Is there any preference for caching in real memory versus the swap file? > Would there still be an advantage to cache that is shifted to swap? Just > curious how things work. > If memory is very stale, it will be replaced quickly -- and that can entail a pageout. You always want memory that is more likely to be used immediately accessible. Imagine this: There is code in sendmail that is normally executed only once. It is better to page that code out (or free it in the case of clean pages) and use that memory as a cache of somesort for more relevent info. -- John dyson@freebsd.org jdyson@nc.com