Skip site navigation (1)Skip section navigation (2)
Date:      30 Jan 2003 09:55:42 -0700
From:      James Gritton <gritton@iserver.com>
To:        freebsd-hackers@FreeBSD.ORG
Subject:   Re: What's the memory footprint of a set of processes?
Message-ID:  <x7znpi60hd.fsf@guppy.dmz.orem.verio.net>
In-Reply-To: Matthew Dillon's message of "Wed, 29 Jan 2003 23:19:24 -0800 (PST)"
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
Matthew Dillon <dillon@apollo.backplane.com> writes:

>     You can also theoretically push into shadow VM objects to locate
>     pages from the parent process that have not yet been COW'd into the
>     child (in the case of a fork()), noting also that these shadow objects
>     might be shared with other children of the parent and by the parent
>     process itself, but under most conditions this information will not
>     be significant and can be ignored.

   Actually, that's just the sort of thing I'm looking for.  The shared case
may be relatively rare, but it tends to be extreme: the processes that use
the most memory seem to be the ones that fork the most - database servers,
java, etc.  The point of this whole thing is an attempt to limit the memory
use of a user (instead of a process), but I don't want to penalize such
sharing.

>     Any vnode object is always shared with other processes mapping the
>     same vnode.  Since this information is backed by a file, figuring out
>     how much 'memory' it represents by any reasonable definition is 
>     guesswork.  The resident page count will represent how much of the
>     vnode is cached, but not how much of the vnode is actually being accessed
>     by the process.

   That's OK - resident count is what I'm interested in.  That, and the swap
approximation (which should suffice) you mentioned for non-vnode objects.

- Jamie

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?x7znpi60hd.fsf>