From owner-freebsd-current@FreeBSD.ORG Thu Sep 30 17:46:12 2010 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 27B6910656A5 for ; Thu, 30 Sep 2010 17:46:12 +0000 (UTC) (envelope-from andre@freebsd.org) Received: from c00l3r.networx.ch (c00l3r.networx.ch [62.48.2.2]) by mx1.freebsd.org (Postfix) with ESMTP id 8AFF08FC29 for ; Thu, 30 Sep 2010 17:46:11 +0000 (UTC) Received: (qmail 21275 invoked from network); 30 Sep 2010 17:38:08 -0000 Received: from unknown (HELO [62.48.0.92]) ([62.48.0.92]) (envelope-sender ) by c00l3r.networx.ch (qmail-ldap-1.03) with SMTP for ; 30 Sep 2010 17:38:08 -0000 Message-ID: <4CA4CCF8.1050300@freebsd.org> Date: Thu, 30 Sep 2010 19:46:32 +0200 From: Andre Oppermann User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.9) Gecko/20100915 Thunderbird/3.1.4 MIME-Version: 1.0 To: freebsd-current@freebsd.org References: <4CA4BCD2.4070303@freebsd.org> <20100930172439.GA34369@freebsd.org> In-Reply-To: <20100930172439.GA34369@freebsd.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: Examining the VM splay tree effectiveness X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 30 Sep 2010 17:46:12 -0000 On 30.09.2010 19:24, Roman Divacky wrote: > are you aware of Summer of Code 2008 project by Mayur Shardul? I remember that there was this project but I never saw any numbers or other outcome of it. Haven't checked p4 to look at the code though. -- Andre > quoting: http://www.freebsd.org/projects/summerofcode-2008.html > > Project: VM Algorithm Improvement > Student: Mayur Shardul > Mentor: Jeff Roberson > Summary: > A new data structure, viz. radix tree, was implemented and used for management of the resident pages. The > objective is efficient use of memory and faster performance. The biggest challenge was to service insert requests > on the data structure without blocking. Because of this constraint the memory allocation failures were not > acceptable, to solve the problem the required memory was allocated at the boot time. Both the data structures were > used in parallel to check the correctness and we also benchmarked the data structures and found that radix trees > gave much better performance over splay trees. > > Ready to enter CVS/SVN: We will investigate some more approaches to handle allocation failures before the new data > structure goes in CVS.