From owner-freebsd-questions@FreeBSD.ORG Thu May 28 17:33:11 2009 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8DA521065670 for ; Thu, 28 May 2009 17:33:11 +0000 (UTC) (envelope-from rwmaillists@googlemail.com) Received: from mail-ew0-f212.google.com (mail-ew0-f212.google.com [209.85.219.212]) by mx1.freebsd.org (Postfix) with ESMTP id 115878FC08 for ; Thu, 28 May 2009 17:33:10 +0000 (UTC) (envelope-from rwmaillists@googlemail.com) Received: by ewy8 with SMTP id 8so2104981ewy.43 for ; Thu, 28 May 2009 10:33:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=gamma; h=domainkey-signature:received:received:date:from:to:subject :message-id:in-reply-to:references:x-mailer:mime-version :content-type:content-transfer-encoding; bh=xeNGjiiilvaKs844BSMQHrvOvPg0rc0pUJrPkaiSAi4=; b=ixxZomXA0RPayvwq9jaD4mcSuzz/Q74pf+e3wRzLSEt8Vd2XfdUWpthlFIu0y+pwlZ yBnBEw+LoEbHbvM75/eMPpcSlfVmmBnyyT35sHT4lz19uhr/XQYjTGEtTIuQ8lp7VPF7 iR+mJbduQGtzpOBAfG0GMZyvAOaW99K+eWnUs= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlemail.com; s=gamma; h=date:from:to:subject:message-id:in-reply-to:references:x-mailer :mime-version:content-type:content-transfer-encoding; b=xFCBZLfawdCfUghWDcnryEMT0MfEKJhh6NdzMJ6zpyfN/YKnhuSesYMaqQFlw0G0Bz lokuI6FpXcol0i7Ai0DwifkKB+OLMT7y/v/BXuNFBJLFUC4hAMWul003k6j7EVdg3vnX Tpu1F5zoQRsKGLVr+mKqx0bvefheRelG8GYZw= Received: by 10.210.79.9 with SMTP id c9mr1310437ebb.61.1243531989700; Thu, 28 May 2009 10:33:09 -0700 (PDT) Received: from gumby.homeunix.com (bb-87-81-140-128.ukonline.co.uk [87.81.140.128]) by mx.google.com with ESMTPS id 10sm486269eyz.41.2009.05.28.10.33.08 (version=SSLv3 cipher=RC4-MD5); Thu, 28 May 2009 10:33:09 -0700 (PDT) Date: Thu, 28 May 2009 18:33:06 +0100 From: RW To: freebsd-questions@freebsd.org Message-ID: <20090528183306.061afc07@gumby.homeunix.com> In-Reply-To: <20090528151738.GC1259@phenom.cordula.ws> References: <20090528151738.GC1259@phenom.cordula.ws> X-Mailer: Claws Mail 3.7.1 (GTK+ 2.16.1; i386-portbld-freebsd7.1) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: superpages? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 May 2009 17:33:11 -0000 On Thu, 28 May 2009 17:17:38 +0200 cpghost wrote: > The following excerpt from: > http://www.freebsd.org/releases/7.2R/relnotes-detailed.html > may be helpful: > > [amd64, i386] The FreeBSD virtual memory subsystem now supports > fully transparent use of superpages for application memory; > application memory pages are dynamically promoted to or demoted from > superpages without any modification to application code. This change > offers the benefit of large page sizes such as improved virtual > memory efficiency and reduced TLB (translation lookaside buffer) > misses without downsides like application changes and virtual memory > inflexibility. Just out of idle curiosity, how does it work at the page queue level. Most of the references to superpages are in pmap.c and vm_reserv.c. I don't see any special handling in the pageout daemon where the inactive and active queues are handled.