From owner-cvs-all@FreeBSD.ORG Thu Dec 9 18:05:05 2004 Return-Path: Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C8F1816A4D0 for ; Thu, 9 Dec 2004 18:05:05 +0000 (GMT) Received: from c00l3r.networx.ch (c00l3r.networx.ch [62.48.2.2]) by mx1.FreeBSD.org (Postfix) with ESMTP id D1F1343D69 for ; Thu, 9 Dec 2004 18:05:04 +0000 (GMT) (envelope-from andre@freebsd.org) Received: (qmail 87579 invoked from network); 9 Dec 2004 17:54:49 -0000 Received: from unknown (HELO freebsd.org) ([62.48.0.53]) (envelope-sender ) by c00l3r.networx.ch (qmail-ldap-1.03) with SMTP for ; 9 Dec 2004 17:54:49 -0000 Message-ID: <41B893D3.59939DEA@freebsd.org> Date: Thu, 09 Dec 2004 19:05:07 +0100 From: Andre Oppermann X-Mailer: Mozilla 4.8 [en] (Windows NT 5.0; U) X-Accept-Language: en MIME-Version: 1.0 To: "Christian S.J. Peron" References: <200412091641.iB9GflnD067866@repoman.freebsd.org> <20041209174457.GA82542@freefall.freebsd.org> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit cc: cvs-src@FreeBSD.org cc: Gleb Smirnoff cc: cvs-all@FreeBSD.org cc: src-committers@FreeBSD.org Subject: Re: cvs commit: src/sys/netinet ip_fw_pfil.c X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 09 Dec 2004 18:05:05 -0000 "Christian S.J. Peron" wrote: > > On Thu, Dec 09, 2004 at 04:41:47PM +0000, Gleb Smirnoff wrote: > > glebius 2004-12-09 16:41:47 UTC > > > > FreeBSD src repository > > > > Modified files: > > sys/netinet ip_fw_pfil.c > > Log: > > Check that DUMMYNET_LOADED before seeking dummynet m_tag. > > I think Sam had some reservations about doing this before, We had some > discussions and in the end it was pretty much concluded that since > tags are rarely present, and m_tag_locate is only called if tags are present, > adding this check unconditionally added a memory write and a compare > for every packet. > > This change may be a mistake unless you can prove some significant > performance gain. Checking for DUMMYNET_LOADED is a simple pointer compare to NULL and doesn't add a memory write. Not a big difference for sure but not hurting either. -- Andre