From owner-freebsd-hackers Wed Sep 3 22:27:48 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id WAA06510 for hackers-outgoing; Wed, 3 Sep 1997 22:27:48 -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 WAA06497 for ; Wed, 3 Sep 1997 22:27:42 -0700 (PDT) Received: (from root@localhost) by dyson.iquest.net (8.8.6/8.8.5) id AAA03237; Thu, 4 Sep 1997 00:27:38 -0500 (EST) From: "John S. Dyson" Message-Id: <199709040527.AAA03237@dyson.iquest.net> Subject: Re: 2.2-stable swap usage? In-Reply-To: <19970904000812.60761@pobox.com> from Brian Campbell at "Sep 4, 97 00:08:12 am" To: brianc@pobox.com (Brian Campbell) Date: Thu, 4 Sep 1997 00:27:38 -0500 (EST) Cc: freebsd-hackers@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-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk Brian Campbell said: > > Mike Smith said: > > The simple answer is that once swap is allocated to a process, it is > > never freed. You have, in the case above, 24M worth of text which at > > some stage has been swapped out, and thus has had swap allocated to it. > > It doesn't mean you have 24M worth of swap currently "in use". > > John S. Dyson wrote: > > Once the pages in MFS or any other process are paged out, those pages will be > > persistant in swap until the process exits (or the memory is explicitly > > deallocated by the process.) > > Ok. So, contrary to what Mike Smith says, pages that belonged to > a process that has since exited will no longer be marked in-use by > swap? > I think that he meant to say it. > > If they are still marked "in-use", is there a program other than > pstat that gives a more accurate picture of how many [active] pages > are in swap? > No. > > So, if 90% of MFS is consumed by files which are later unlinked > (and not in use by any process), is swap thereafter limited to 10% > of its original size? > If you use MFS, it's swap allocation (whatever it is) will persist until you unmount. I have thought about cleaning MFS up, but there are many more important things to do, and am overloaded trying to do them... :-(. -- John dyson@freebsd.org jdyson@nc.com