From owner-svn-src-head@FreeBSD.ORG Sat Nov 2 22:36:13 2013 Return-Path: Delivered-To: svn-src-head@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id 8C9F6EBF; Sat, 2 Nov 2013 22:36:13 +0000 (UTC) (envelope-from mark@grondar.org) Received: from gromit.grondar.org (grandfather.grondar.org [IPv6:2a01:348:0:15:5d59:5c20:0:2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 4EEAA2C46; Sat, 2 Nov 2013 22:36:13 +0000 (UTC) Received: from [2001:470:9174:1:d5dd:fe5d:5b9d:33d2] by gromit.grondar.org with esmtpsa (TLSv1:AES128-SHA:128) (Exim 4.80.1 (FreeBSD)) (envelope-from ) id 1Vcjnb-0001kN-J7; Sat, 02 Nov 2013 22:36:11 +0000 Subject: Re: svn commit: r257535 - head/sys/netgraph Mime-Version: 1.0 (Mac OS X Mail 7.0 \(1816\)) Content-Type: multipart/signed; boundary="Apple-Mail=_4008F7B3-6AF9-4838-9C8C-F213184AB203"; protocol="application/pgp-signature"; micalg=pgp-sha512 From: Mark R V Murray In-Reply-To: <20131103091238.S1004@besplex.bde.org> Date: Sat, 2 Nov 2013 22:35:59 +0000 Message-Id: <38F2745D-B252-495E-96D3-B4139165AB95@grondar.org> References: <201311020011.rA20BchL020170@svn.freebsd.org> <20131102151309.A1102@besplex.bde.org> <76BC3F76-ED5E-42F0-BCCE-271EA723698E@grondar.org> <0FD2B8FA-7DD7-4626-95F6-BB64B648E81A@grondar.org> <20131103091238.S1004@besplex.bde.org> To: Bruce Evans X-Mailer: Apple Mail (2.1816) X-SA-Score: -1.0 Cc: "svn-src-head@freebsd.org" , "svn-src-all@freebsd.org" , "src-committers@freebsd.org" X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 02 Nov 2013 22:36:13 -0000 --Apple-Mail=_4008F7B3-6AF9-4838-9C8C-F213184AB203 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 On 2 Nov 2013, at 22:28, Bruce Evans wrote: > On Sat, 2 Nov 2013, Mark R V Murray wrote: >=20 >> On 2 Nov 2013, at 09:32, Mark R V Murray wrote: >>>> Mark - did you initially mean the address of the mbuf m_data = pointer, >>>> or the data payload itself? >>>=20 >>> As Bruce says - the address of payload data itself. We don=92t have = 12-byte pointers in FreeBSD. :-) >>=20 >> Cancel that. >>=20 >> The address passed must be the address of the m_data field in the = mbuf structure. The harvested data is 12 bytes from that address = forward, so not the data pointed to by that m_data pointer but the = pointer value itself and some following junk too. >=20 > Is that really worth using? Yes. Most of the value comes from the timing. The 12 bytes we snatch on = the way past are opportunistic, and hopefully cheap due to being = in-cache. M --=20 --=20 Mark R V Murray --Apple-Mail=_4008F7B3-6AF9-4838-9C8C-F213184AB203 Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP using GPGMail -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.22 (Darwin) Comment: GPGTools - http://gpgtools.org iQCVAwUBUnV+Vd58vKOKE6LNAQrciQP+PtQA6vKGhlaBYJ+6HdXWzwaXhEHn+/1l TQ8h6YGGFJ17BHjP9e2QoxYgp1zByXUF8C3DkdXezGj+TbnTjN4I+7udoV9jdKV0 64/4N1SpuVcwzks6h+OW1j5/7eC/Xy8vT59XreF6wplfZxU8ODbPFwFRXUgCBdvo AihilNgqooE= =KV+c -----END PGP SIGNATURE----- --Apple-Mail=_4008F7B3-6AF9-4838-9C8C-F213184AB203--