From owner-freebsd-hackers Wed Apr 5 04:02:57 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id EAA15608 for hackers-outgoing; Wed, 5 Apr 1995 04:02:57 -0700 Received: from labinfo.iet.unipi.it (labinfo.iet.unipi.it [131.114.9.5]) by freefall.cdrom.com (8.6.10/8.6.6) with ESMTP id EAA15586 for ; Wed, 5 Apr 1995 04:02:34 -0700 Received: from localhost (luigi@localhost) by labinfo.iet.unipi.it (8.6.5/8.6.5) id MAA00336; Wed, 5 Apr 1995 12:48:51 +0200 From: Luigi Rizzo Message-Id: <199504051048.MAA00336@labinfo.iet.unipi.it> Subject: Re: swap always use at least 64KB ? To: davidg@Root.COM Date: Wed, 5 Apr 1995 12:48:51 +0200 (MET DST) Cc: hackers@FreeBSD.org In-Reply-To: <199504042340.QAA00208@corbin.Root.COM> from "David Greenman" at Apr 4, 95 04:39:48 pm X-Mailer: ELM [version 2.4 PL23] Content-Type: text Content-Length: 1175 Sender: hackers-owner@FreeBSD.org Precedence: bulk > >no activity going on... Swap partition, when in use, are always > >reported with at least 64 KB in use. > > > >Is there any explaination ? > > The first swap block is always pre-allocated. This was done to work around > a problem with people putting their swap partition at the beginning of their > disk (the system would happily try to destroy the label). I suppose it would > be better to change swapinfo/pstat to not include the first block of swap > space in its report. That depends. Seeing "Used" > 0 is a nice reminder that the partition is in use and you cannot unmount it (whatever it means; I am playing with vnodes and swap-on-files these days). Also, given the above explaination, that 64K are really lost swap space, so it is better to keep it in the statistics. It doesn't hurt, once you know why. Luigi ==================================================================== Luigi Rizzo Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it Universita' di Pisa tel: +39-50-568533 via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 ====================================================================