Date: Wed, 29 Jan 2003 22:44:48 -0800 From: David Schultz <dschultz@uclink.Berkeley.EDU> To: James Gritton <gritton@iserver.com> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: What's the memory footprint of a set of processes? Message-ID: <20030130064448.GA7258@HAL9000.homeunix.com> In-Reply-To: <x7k7gnog4m.fsf@guppy.dmz.orem.verio.net> References: <Pine.BSF.4.21.0301291145030.25856-100000@InterJet.elischer.org> <x7k7gnog4m.fsf@guppy.dmz.orem.verio.net>
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Thus spake James Gritton <gritton@iserver.com>: > The object's ref_count hasn't changed, which is what I meant about seeing > reference counts in the kernel that were apparently not counting what I'm > looking for. I did see a ref_count increase on the first object > (presumably the text image), but nothing on the allocated memory. > > It seems the object level isn't fine enough, but the deeper I go into the > VM code, the more confused I become. In this forked process example, what > happens when I alter a few COW pages in the currently-shared object? > Apparently a shadow object is created, but it claims to be the same size as > the original object. True, but I know it's not actually using that many > pages, since most of them are still validly shared. System usage numbers > tell me this is true, but I can't find what in the process or object data > structures reflect this fact. No, you don't have enough information. Even if you knew which objects shadowed which, I still don't think you would have enough information. You want to account for physical pages, so you should be looking at vm_page structures. AFAIK, there isn't an interface to do that, but one shouldn't be too hard to implement. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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