From owner-freebsd-hackers Thu Jan 30 16:14:47 2003 Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 0808C37B405 for ; Thu, 30 Jan 2003 16:14:46 -0800 (PST) Received: from HAL9000.homeunix.com (12-233-57-224.client.attbi.com [12.233.57.224]) by mx1.FreeBSD.org (Postfix) with ESMTP id D552743F75 for ; Thu, 30 Jan 2003 16:14:39 -0800 (PST) (envelope-from dschultz@uclink.Berkeley.EDU) Received: from HAL9000.homeunix.com (localhost [127.0.0.1]) by HAL9000.homeunix.com (8.12.6/8.12.5) with ESMTP id h0V0EbNt010911; Thu, 30 Jan 2003 16:14:37 -0800 (PST) (envelope-from dschultz@uclink.Berkeley.EDU) Received: (from das@localhost) by HAL9000.homeunix.com (8.12.6/8.12.5/Submit) id h0V0EaHm010910; Thu, 30 Jan 2003 16:14:36 -0800 (PST) (envelope-from dschultz@uclink.Berkeley.EDU) Date: Thu, 30 Jan 2003 16:14:36 -0800 From: David Schultz To: Matthew Dillon Cc: James Gritton , freebsd-hackers@FreeBSD.ORG Subject: Re: What's the memory footprint of a set of processes? Message-ID: <20030131001436.GA10856@HAL9000.homeunix.com> Mail-Followup-To: Matthew Dillon , James Gritton , freebsd-hackers@FreeBSD.ORG References: <20030130064448.GA7258@HAL9000.homeunix.com> <200301300719.h0U7JOfI086054@apollo.backplane.com> <20030130091419.GA7776@HAL9000.homeunix.com> <200301301923.h0UJNT0l089037@apollo.backplane.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200301301923.h0UJNT0l089037@apollo.backplane.com> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Thus spake Matthew Dillon : > It's not possible to get a wholely accurate count no matter what > you do. For example, to truely know whether a process is using > a page you have to run through the process's page table (PMAP), > access the vm_page, then locate where in the shadow chain the VM object > the vm_page belongs to resides. But since hardware page tables are > throw-away, the system could very well have thrown away whole page > tables so this method is no more accurate then any other. Thanks for the explanations! I still don't understand why this doesn't work, assuming you don't care about nonresident pages: for each process p in the set for each map entry e in p->vmspace->vm_map for each page m in e->object.vm_object->memq if I haven't seen this m.phys_addr yet in the scan resident_pages++ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message