From users-return-191245-apmail-tomcat-users-archive=tomcat.apache.org@tomcat.apache.org Fri Feb 06 04:46:12 2009 Return-Path: Delivered-To: apmail-tomcat-users-archive@www.apache.org Received: (qmail 96877 invoked from network); 6 Feb 2009 04:46:12 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.2) by minotaur.apache.org with SMTP; 6 Feb 2009 04:46:12 -0000 Received: (qmail 28462 invoked by uid 500); 6 Feb 2009 04:45:59 -0000 Delivered-To: apmail-tomcat-users-archive@tomcat.apache.org Received: (qmail 28429 invoked by uid 500); 6 Feb 2009 04:45:59 -0000 Mailing-List: contact users-help@tomcat.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: "Tomcat Users List" Delivered-To: mailing list users@tomcat.apache.org Received: (qmail 28418 invoked by uid 99); 6 Feb 2009 04:45:59 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 05 Feb 2009 20:45:59 -0800 X-ASF-Spam-Status: No, hits=-0.0 required=10.0 tests=SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: local policy) Received: from [192.61.61.109] (HELO usea-naimss4.unisys.com) (192.61.61.109) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 06 Feb 2009 04:45:49 +0000 Received: from usea-nagw3.na.uis.unisys.com ([129.224.72.20]) by usea-naimss4 with InterScan Message Security Suite; Thu, 05 Feb 2009 22:45:27 -0600 Received: from usea-nagw3.na.uis.unisys.com ([129.224.72.55]) by usea-nagw3.na.uis.unisys.com with Microsoft SMTPSVC(6.0.3790.3959); Thu, 5 Feb 2009 22:45:27 -0600 Received: from usea-nahubcas1.na.uis.unisys.com ([129.224.76.114]) by usea-nagw3.na.uis.unisys.com with Microsoft SMTPSVC(6.0.3790.3959); Thu, 5 Feb 2009 22:45:27 -0600 Received: from USEA-EXCH7.na.uis.unisys.com ([129.224.76.38]) by usea-nahubcas1.na.uis.unisys.com ([129.224.76.114]) with mapi; Thu, 5 Feb 2009 22:45:26 -0600 From: "Caldarale, Charles R" To: Tomcat Users List Date: Thu, 5 Feb 2009 22:45:25 -0600 Subject: RE: Should I use the -server switch? Thread-Topic: Should I use the -server switch? Thread-Index: AcmH+nmiPkAFYmsVTDSvX8F6N60KLQAGgAPw Message-ID: <0AAE5AB84B013E45A7B61CB66943C17215B611B609@USEA-EXCH7.na.uis.unisys.com> References: <498B927D.6080402@gmail.com> In-Reply-To: <498B927D.6080402@gmail.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginalArrivalTime: 06 Feb 2009 04:45:27.0145 (UTC) FILETIME=[BB192D90:01C98815] X-Virus-Checked: Checked by ClamAV on apache.org > From: Bill Davidson [mailto:billdsd@gmail.com] > Subject: Should I use the -server switch? > > Tomcat 6.0.18 > JVM: Sun 1.6.0_11 64-bit for Linux Most of the 64-bit Sun JVMs come only in -server mode, no -client version. = Run "java -version" (without the quotes) to see what the default mode is. > What does this switch really do anyway? There are two byte-code to native compilers in the JVM, called client and s= erver (or C1 and C2, internally). The C1 compiler focuses on fast compilat= ions, whereas C2 tries to generate the most optimum code. The C2 compiler = will actually recompile methods multiple times to improve optimization as i= t learns more about how methods are being used. C2-generated code is often= 10-15% faster than C1 code, but it takes a *lot* longer to compile things. The current HotSpot JVMs only allow you to select one or the other mode, an= d you're stuck with it for the life of that JVM execution. Sun is moving t= he JVM towards tiered compilations, where both the C1 and C2 compilers will= work together, with C1 being used initially, and C2 applied to heavily use= d pieces of the application. - Chuck THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY MA= TERIAL and is thus for use only by the intended recipient. If you received = this in error, please contact the sender and delete the e-mail and its atta= chments from all computers. --------------------------------------------------------------------- To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org For additional commands, e-mail: users-help@tomcat.apache.org