Date: Sat, 2 Nov 2013 22:35:59 +0000 From: Mark R V Murray <mark@grondar.org> To: Bruce Evans <brde@optusnet.com.au> Cc: "svn-src-head@freebsd.org" <svn-src-head@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>, "src-committers@freebsd.org" <src-committers@freebsd.org> Subject: Re: svn commit: r257535 - head/sys/netgraph Message-ID: <38F2745D-B252-495E-96D3-B4139165AB95@grondar.org> In-Reply-To: <20131103091238.S1004@besplex.bde.org> References: <201311020011.rA20BchL020170@svn.freebsd.org> <20131102151309.A1102@besplex.bde.org> <CAJ-VmokeP5Z2d7jZ-j-Thrh_VuQBKGpKC9nWG%2BQfhR0f6wzF9w@mail.gmail.com> <76BC3F76-ED5E-42F0-BCCE-271EA723698E@grondar.org> <0FD2B8FA-7DD7-4626-95F6-BB64B648E81A@grondar.org> <20131103091238.S1004@besplex.bde.org>
index | next in thread | previous in thread | raw e-mail
[-- Attachment #1 --] On 2 Nov 2013, at 22:28, Bruce Evans <brde@optusnet.com.au> wrote: > On Sat, 2 Nov 2013, Mark R V Murray wrote: > >> On 2 Nov 2013, at 09:32, Mark R V Murray <mark@grondar.org> wrote: >>>> Mark - did you initially mean the address of the mbuf m_data pointer, >>>> or the data payload itself? >>> >>> As Bruce says - the address of payload data itself. We don’t have 12-byte pointers in FreeBSD. :-) >> >> Cancel that. >> >> 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. > > 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 -- -- Mark R V Murray [-- Attachment #2 --] -----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-----help
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?38F2745D-B252-495E-96D3-B4139165AB95>