Date: Thu, 30 Jan 2003 16:14:36 -0800 From: David Schultz <dschultz@uclink.Berkeley.EDU> To: Matthew Dillon <dillon@apollo.backplane.com> Cc: James Gritton <gritton@iserver.com>, freebsd-hackers@FreeBSD.ORG Subject: Re: What's the memory footprint of a set of processes? Message-ID: <20030131001436.GA10856@HAL9000.homeunix.com> In-Reply-To: <200301301923.h0UJNT0l089037@apollo.backplane.com> References: <Pine.BSF.4.21.0301291145030.25856-100000@InterJet.elischer.org> <x7k7gnog4m.fsf@guppy.dmz.orem.verio.net> <20030130064448.GA7258@HAL9000.homeunix.com> <200301300719.h0U7JOfI086054@apollo.backplane.com> <20030130091419.GA7776@HAL9000.homeunix.com> <200301301923.h0UJNT0l089037@apollo.backplane.com>
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Thus spake Matthew Dillon <dillon@apollo.backplane.com>: > 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
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