From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <15328399.1162222490427.JavaMail.ngmail@domain.hid> Date: Mon, 30 Oct 2006 16:34:50 +0100 (CET) From: "M. Koehrer" Subject: Re: [Xenomai-help] Results of xenomai's latency test vs. RTAI's In-Reply-To: <1162219241.5188.21.camel@domain.hid> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable References: <1162219241.5188.21.camel@domain.hid> <1162208265.4955.17.camel@domain.hid> <21364954.1162202747823.JavaMail.ngmail@domain.hid> <16802252.1162217706570.JavaMail.ngmail@domain.hid> List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: rpm@xenomai.org, mathias_koehrer@domain.hid Cc: xenomai@xenomai.org Hi everybody, I have repeated the test using a parallel stress test (dd if=3D/dev/sda of= =3D/dev/null, I have a SATA harddisk). The results are that my RTAI latency of 4=B5s is not valid, here the latenc= y is about 26=B5s. However, xenomai shows a higher latency of about 40=B5s. The interesting thing is, that without load RTAI seems to run very long in = a very=20 low latency region, at the same setup xenomai shows large latencies earlier= . Well, I have repeated these tests on a different PC that has a server mainb= oard and=20 a Pentium D 4 (real dual core) CPU. The results (measured under load) are much better here: RTAI shows a latency of about 6=B5s Xenomai shows a latency of about 10=B5s. Both values are acceptable, however I wonder where the difference comes fro= m? Thanks for all the feedback on that issue! Regards Mathias > > I have rebuild my system using V2.2.4 of xenomai. > > Also, I had a look to reuse the kernel configuration from the 2.4.33 RT= AI > system. > > However, the results are more or less the same. > > The only kernel module I have loaded is the "tg3" network driver, the > chipset of the=20 > > PC (ICH6) is supported by the SMI detection and it is activated. > >=20 >=20 > On such hw, you may want to enable the following: > CONFIG_BLK_DEV_IDEDMA_PCI=3Dy > CONFIG_BLK_DEV_IDEDMA=3Dy > CONFIG_IDEDMA_AUTO=3Dy >=20 > > I have enclosed my kernel configuration, perhaps this can help to ident= ify > an issue. > > I do not have X11 running, it is a text-mode only system that is > controlled via telnet from > > another PC. > >=20 > > I'll try to do a stress test on the RTAI system as well. > >=20 >=20 > You could try running RTAI 3.3 over 2.6.17 with the very same config > file too (Xenomai opts aside, of course), so you could rule out any > configuration problem if the gap still exists. --=20 Mathias Koehrer mathias_koehrer@domain.hid Viel oder wenig? Schnell oder langsam? Unbegrenzt surfen + telefonieren ohne Zeit- und Volumenbegrenzung? DAS TOP ANGEBOT JETZT bei Arcor: g=FCnsti= g und schnell mit DSL - das All-Inclusive-Paket f=FCr clevere Doppel-Sparer, nur 44,85 =80 inkl. DSL- und ISDN-Grundgeb=FChr! http://www.arcor.de/rd/emf-dsl-2