From owner-svn-src-user@FreeBSD.ORG Sun Mar 17 15:27:27 2013 Return-Path: Delivered-To: svn-src-user@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id 3AAA4506; Sun, 17 Mar 2013 15:27:27 +0000 (UTC) (envelope-from attilio@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) by mx1.freebsd.org (Postfix) with ESMTP id 2BFD3752; Sun, 17 Mar 2013 15:27:27 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.6/8.14.6) with ESMTP id r2HFRRU1045462; Sun, 17 Mar 2013 15:27:27 GMT (envelope-from attilio@svn.freebsd.org) Received: (from attilio@localhost) by svn.freebsd.org (8.14.6/8.14.5/Submit) id r2HFRR1f045461; Sun, 17 Mar 2013 15:27:27 GMT (envelope-from attilio@svn.freebsd.org) Message-Id: <201303171527.r2HFRR1f045461@svn.freebsd.org> From: Attilio Rao Date: Sun, 17 Mar 2013 15:27:27 +0000 (UTC) To: src-committers@freebsd.org, svn-src-user@freebsd.org Subject: svn commit: r248424 - user/attilio/vmcontention/sys/vm X-SVN-Group: user MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-user@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "SVN commit messages for the experimental " user" src tree" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 17 Mar 2013 15:27:27 -0000 Author: attilio Date: Sun Mar 17 15:27:26 2013 New Revision: 248424 URL: http://svnweb.freebsd.org/changeset/base/248424 Log: Expand ambiguous comments some more. Requested by: alc Modified: user/attilio/vmcontention/sys/vm/vm_radix.c Modified: user/attilio/vmcontention/sys/vm/vm_radix.c ============================================================================== --- user/attilio/vmcontention/sys/vm/vm_radix.c Sun Mar 17 15:18:15 2013 (r248423) +++ user/attilio/vmcontention/sys/vm/vm_radix.c Sun Mar 17 15:27:26 2013 (r248424) @@ -35,11 +35,17 @@ * of this code must achieve highest possible performance. * * The implementation takes into account the following rationale: - * - Size of the nodes should be as small as possible. - * - There is no bias toward lookup operations over inserts or removes, - * and vice-versa. - * - On average not many nodes are expected to be full, hence level - * compression may just complicate things. + * - Size of the nodes should be as small as possible but still big enough + * to avoid a large maximum depth for the trie. This is a balance + * between the necessity to not wire too much physical memory for the nodes + * and the necessity to avoid too much cache pollution during the trie + * operations. + * - There is not a huge bias toward the number of lookup operations over + * the number of insert and remove operations. This basically implies + * that optimizations supposedly helping one operation but hurting the + * other might be carefully evaluated. + * - On average not many nodes are expected to be fully populated, hence + * level compression may just complicate things. */ #include