From owner-freebsd-hackers Sun Aug 19 12: 9: 3 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from earth.backplane.com (earth-nat-cw.backplane.com [208.161.114.67]) by hub.freebsd.org (Postfix) with ESMTP id 2CEE937B411; Sun, 19 Aug 2001 12:09:01 -0700 (PDT) (envelope-from dillon@earth.backplane.com) Received: (from dillon@localhost) by earth.backplane.com (8.11.4/8.11.2) id f7JJ8t445840; Sun, 19 Aug 2001 12:08:55 -0700 (PDT) (envelope-from dillon) Date: Sun, 19 Aug 2001 12:08:55 -0700 (PDT) From: Matt Dillon Message-Id: <200108191908.f7JJ8t445840@earth.backplane.com> To: David Greenman Cc: hackers@freebsd.org, murray@freebsd.org, jkh@freebsd.org Subject: Re: Recommendation for minor KVM adjustments for the release References: <200108181549.f7IFntw39740@earth.backplane.com> <20010818155924.D63814@nexus.root.com> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG : :> There are two things I would like to commit for the release: :> :> - I would like to cap the SWAPMETA zone reservation to 70MB, :> which allows us to manage a maximum of 29GB worth of swapped :> out data. :> :> This is plenty and saves us 94MB of KVM which is roughly :> equivalent to 30,000 nmbclusters/mbufs. : : It's seems really hard to justify even that much SWAPMETA. A more :reasonable amount would be more like 20MB. : :> - I would like to cap the size of the buffer cache at 200MB, :> giving us another 70MB or so of KVM which is equivalent to :> another 30,000 or so nmbclusters. : : That also seems like overkill for the vast majority of systems. : : :-DG : :David Greenman It's not a 1:1 mapping. There is some sparseness to the way SWAPMETA structures are used so 29GB worth of swap-meta supported VM may wind up only being 15GB of actually-swapped-out-dat in reallity. It depends very heavily on the applications being run. -Matt To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message