From owner-freebsd-arch@FreeBSD.ORG  Sun Oct 21 02:33:06 2012
Return-Path: <owner-freebsd-arch@FreeBSD.ORG>
Delivered-To: freebsd-arch@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52])
 by hub.freebsd.org (Postfix) with ESMTP id 5A67281C;
 Sun, 21 Oct 2012 02:33:06 +0000 (UTC)
 (envelope-from marcel@xcllnt.net)
Received: from mail.xcllnt.net (mail.xcllnt.net [70.36.220.4])
 by mx1.freebsd.org (Postfix) with ESMTP id 2EB048FC0A;
 Sun, 21 Oct 2012 02:33:06 +0000 (UTC)
Received: from marcelm-sslvpn-nc.jnpr.net (natint3.juniper.net [66.129.224.36])
 (authenticated bits=0)
 by mail.xcllnt.net (8.14.5/8.14.5) with ESMTP id q9L2Wi1x035388
 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NO);
 Sat, 20 Oct 2012 19:33:05 -0700 (PDT)
 (envelope-from marcel@xcllnt.net)
Content-Type: text/plain; charset=us-ascii
Mime-Version: 1.0 (Mac OS X Mail 6.2 \(1499\))
Subject: Re: Behavior of madvise(MADV_FREE)
From: Marcel Moolenaar <marcel@xcllnt.net>
In-Reply-To: <508305A6.4090106@rice.edu>
Date: Sat, 20 Oct 2012 19:33:39 -0700
Content-Transfer-Encoding: quoted-printable
Message-Id: <FC99AD0B-88AA-4D96-BDA8-1B566297B62A@xcllnt.net>
References: <9FEBC10C-C453-41BE-8829-34E830585E90@xcllnt.net>
 <4835.1350062021@critter.freebsd.dk>
 <E6A52D27-0D6A-4175-9ECA-ADE25BFF35C2@xcllnt.net>
 <F71ACE9D-297E-4565-BB8D-D95D46D90708@freebsd.org>
 <F67D539D-8BE3-4817-8466-C76DE43AE252@xcllnt.net> <5082F0F3.1070102@rice.edu>
 <92742.1350761696@critter.freebsd.dk> <508305A6.4090106@rice.edu>
To: Alan Cox <alc@rice.edu>
X-Mailer: Apple Mail (2.1499)
Cc: Jason Evans <jasone@freebsd.org>, Poul-Henning Kamp <phk@phk.freebsd.dk>,
 Tim LaBerge <tlaberge@juniper.net>,
 "freebsd-arch@freebsd.org Arch" <freebsd-arch@freebsd.org>
X-BeenThere: freebsd-arch@freebsd.org
X-Mailman-Version: 2.1.14
Precedence: list
List-Id: Discussion related to FreeBSD architecture <freebsd-arch.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/options/freebsd-arch>,
 <mailto:freebsd-arch-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-arch>
List-Post: <mailto:freebsd-arch@freebsd.org>
List-Help: <mailto:freebsd-arch-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-arch>,
 <mailto:freebsd-arch-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 21 Oct 2012 02:33:06 -0000


On Oct 20, 2012, at 1:12 PM, Alan Cox <alc@rice.edu> wrote:

> On 10/20/2012 14:34, Poul-Henning Kamp wrote:
>> --------
>> In message<5082F0F3.1070102@rice.edu>, Alan Cox writes:
>>=20
>>> I'm sympathetic.  Once upon a time, I was often called upon to =
explain
>>> to network administrators why their idle web cache didn't have =
oodles of
>>> "free" memory and how this wasn't a problem.
>> You too ?   :-)
>>=20
>>> I think that you're being a bit too pessimistic here.  If your use =
case
>>> really corresponds to "this memory is free and will not be reused =
(or
>>> reallocated for a very long time)"
>> Which brings me to a question I have wondered:  Why not simply
>> munmap(2) it until you need it again ?
>>=20
>=20
> My recollection is that Marcel said that the memory was acquired via =
sbrk(2).

Correct.

--=20
Marcel Moolenaar
marcel@xcllnt.net