From owner-freebsd-questions Fri Jun 30 5:34:36 2000 Delivered-To: freebsd-questions@freebsd.org Received: from majordomo2.umd.edu (majordomo2.umd.edu [128.8.10.7]) by hub.freebsd.org (Postfix) with ESMTP id E501A37C4D1 for ; Fri, 30 Jun 2000 05:34:24 -0700 (PDT) (envelope-from culverk@wam.umd.edu) Received: from rac1.wam.umd.edu (root@rac1.wam.umd.edu [128.8.10.141]) by majordomo2.umd.edu (8.9.3/8.9.3) with ESMTP id IAA17496; Fri, 30 Jun 2000 08:34:15 -0400 (EDT) Received: from rac1.wam.umd.edu (sendmail@localhost [127.0.0.1]) by rac1.wam.umd.edu (8.9.3/8.9.3) with SMTP id IAA07481; Fri, 30 Jun 2000 08:34:16 -0400 (EDT) Received: from localhost (culverk@localhost) by rac1.wam.umd.edu (8.9.3/8.9.3) with ESMTP id IAA07477; Fri, 30 Jun 2000 08:34:16 -0400 (EDT) X-Authentication-Warning: rac1.wam.umd.edu: culverk owned process doing -bs Date: Fri, 30 Jun 2000 08:34:16 -0400 (EDT) From: Kenneth Wayne Culver To: Paul Herman Cc: freebsd-questions@FreeBSD.ORG Subject: Re: what is active/inactive memory (was Re: memory leak?) In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Well, yeah, I think we're doing VM next week. Either way, thanks... :-) I wish this class was based on -CURRENT instead of 2.2.x though.. I know the -CURRENT code so much better than the 2.2.x code. ================================================================= | Kenneth Culver | FreeBSD: The best NT upgrade | | Unix Systems Administrator | ICQ #: 24767726 | | and student at The | AIM: muythaibxr | | The University of Maryland, | Website: (Under Construction) | | College Park. | http://www.wam.umd.edu/~culverk/| ================================================================= On Fri, 30 Jun 2000, Paul Herman wrote: > On Thu, 29 Jun 2000, Kenneth Wayne Culver wrote: > > > Hope I wasn't too mean :-) hehe... I think actually that we are covering > > the vm system (at least in 2.2.5, kinda old, but I'm sure that knowing > > 2.2.x's system, I could bring my self up to date on -CURRENT's vm > > system) pretty soon in this class. I can't wait. > > Then be careful of those trick questions which just bit me :) After > all, strictly speaking, there is no single concept in the kernel of > what "active" memory is, which you can see in > > 1) vmmeter->v_active_count: the one top(1) reports (pages with a > non-zero reference count.) > > 2) vmtotal->t_avm: reported by vmstat(8) (virtual pages used by > programs running in the last 20 seconds) > > 3) vmtotal->t_arm: reported by systat(1) (resident pages used > by programs running in the last 20 seconds) > > 1) and 3) are probably the most useful. In most cases, there is more > memory available to you than just "Inactive + Cache + Free", becase > some of the active memory (in the 1st sense) isn't really active (in > the 3rd sense), as would be the case with the original poster's memory > leak problem. This is clear to see with systat(1). > > So, be careful if you only have a multiple choice test!... It seems > nowadays most people just use top, so if you need only one answer to > "what is active/inactive memory" I guess 1) wins. :) "which objects > can be found in the active/inactive queue" on the other hand, would be > much easier to answer. > > -Paul. > > > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message