Date: Thu, 30 Jan 2003 01:14:19 -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: <20030130091419.GA7776@HAL9000.homeunix.com> In-Reply-To: <200301300719.h0U7JOfI086054@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>
next in thread | previous in thread | raw e-mail | index | archive | help
Thus spake Matthew Dillon <dillon@apollo.backplane.com>: > Generally speaking I don't think you have to go into this level of > detail to figure out approximate real memory use. Just look at the > output of the /proc/PID/map and pull out the 'default' or 'swap' > lines. Ignore the 'vnode' lines. ... > Now you have two metrics. You can calculate the size based on the > range (the first two arguments). (addressB - addressA), and you can get > the total number of resident pages from the third argument. What you > can't do easily is figure out the total allocation because that is > actually going to be resident pages + swapped pages. swapped pages is > not included in the proc output. I think the original poster wanted to know the real memory use of a set of processes, taking sharing into account. I don't see how your approach could do that. Even if you knew the structure of the shadow chain, you would have to know specifically which pages had been COWed, no? I thought counting vm_page structures would be the way to go... I really want to find the time to learn all this stuff better. I still don't know the difference between COW and NEEDS_COPY, or why the pageout daemon seems to be biased against shared pages, or a lot of things about pv_entry structures. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030130091419.GA7776>