From owner-freebsd-arch Wed Feb 27 12:52:18 2002 Delivered-To: freebsd-arch@freebsd.org Received: from hawk.mail.pas.earthlink.net (hawk.mail.pas.earthlink.net [207.217.120.22]) by hub.freebsd.org (Postfix) with ESMTP id C2CB137B400 for ; Wed, 27 Feb 2002 12:52:13 -0800 (PST) Received: from pool0139.cvx21-bradley.dialup.earthlink.net ([209.179.192.139] helo=mindspring.com) by hawk.mail.pas.earthlink.net with esmtp (Exim 3.33 #1) id 16gB3W-0004rR-00; Wed, 27 Feb 2002 12:52:07 -0800 Message-ID: <3C7D46BF.CE88CDEA@mindspring.com> Date: Wed, 27 Feb 2002 12:51:11 -0800 From: Terry Lambert X-Mailer: Mozilla 4.7 [en]C-CCK-MCD {Sony} (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Matthew Dillon Cc: Alfred Perlstein , Julian Elischer , Jeff Roberson , arch@FreeBSD.ORG Subject: Re: Slab allocator References: <200202271926.g1RJQCm29905@apollo.backplane.com> <20020227194256.GR80761@elvis.mu.org> <200202271955.g1RJtAj30178@apollo.backplane.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Matthew Dillon wrote: > :It's basically the pre-emption stuff you guys are wondering about > :along with the possiblity of free'ing back to another cpu's > :cache that may be an issue. > : > :Jeff, are you fee'ing memory back to the cache it was initially > :allocated from or not? > > I don't know what Jeff is doing there but I do seem to recall a > paper from somewhere that indicated it was more efficient to free memory > to the current cpu's per-cpu cache rather then back to the original > cpu's cache because the current cpu's hardware L1/L2 cache likely already > has mastership of the memory. I think Linux does things this way. I think you are thinking of: Experience With an Efficient Parallel Kernel Memory Allocator Paul E. McKenney Jack Slingwine Phil Krueger Sequent Computer Systems, Inc. The paper is available at: http://citeseer.nj.nec.com/484408.html They used a "second chance" three layer coelescing strategy, where a third level coelesced freed objects back into pages for return to the host OS. -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message