From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <442C472B.2090300@domain.hid> Date: Thu, 30 Mar 2006 23:01:31 +0200 From: Jan Kiszka MIME-Version: 1.0 Subject: Re: [Xenomai-help] gigabit rate packet processing with xenomai References: <2cf1ee820603280009r5adec759h99aa69809f68b457@domain.hid> <44296668.10300@domain.hid> <2cf1ee820603300724w1335df09nf4d2abb0755107d5@domain.hid> In-Reply-To: <2cf1ee820603300724w1335df09nf4d2abb0755107d5@domain.hid> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig2C9E9E873C4177F4512E673C" Sender: jan.kiszka@domain.hid List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: emin ak Cc: xenomai@xenomai.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig2C9E9E873C4177F4512E673C Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable emin ak wrote: > Dear All; > Thanks for the answers firstly. > I'am using linux (and also xenomai ) for a powerpc (PQ3/MPC8540) and > will use on chip gigabit ethernet controller (tsec) that is not > supported on rt-net yet (maybe untill I'll write one:) > In my opinion and my basic tests shows that context switch times and > system call latecies in linux decrease user space performance > significally even with highest RT_FIFO priority and this reasons > prevent my gigabit rate data processing in user space. > I think I'll firstly choose un-deterministical way, write a realtime > user space thread that process the data coming from linux ethernet > driver, if it fails, I'll adapt the driver for rt-net or wait for the > up-coming realtime-preemptive patch. If you can live with a certain amount of deadline misses, this is probably the most reasonable approach. And preempt-rt will further improve the quality of service but will still not be able to /guarantee/ networking latencies (the network stack is not explicitly included in the latency improvements under preempt-rt, resource allocation remains nondeterministic). Jan --------------enig2C9E9E873C4177F4512E673C Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFELEcrniDOoMHTA+kRAv3oAJ47vAJPwGUwycp1/zrYlsbdglAmGQCfRUw7 p4dyL/JAlZWr9XLPV9GfPPI= =0Bax -----END PGP SIGNATURE----- --------------enig2C9E9E873C4177F4512E673C--