From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4551FDF9.1070401@domain.hid> Date: Wed, 08 Nov 2006 16:55:37 +0100 From: Jan Kiszka MIME-Version: 1.0 Subject: Re: [Xenomai-help] LATENCIES > 100 us or CRASH WITH X (with joints pieces) References: <4551F2E5.5050200@domain.hid> <4551F62A.9030607@domain.hid> <4551FC33.4080208@domain.hid> In-Reply-To: <4551FC33.4080208@domain.hid> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig0A8F44C518900091F0949246" 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: Jean-Luc Pamart Cc: xenomai-help This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig0A8F44C518900091F0949246 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable Jean-Luc Pamart wrote: > Jan Kiszka a =E9crit : >> Jean-Luc Pamart wrote: >> =20 >>> Hello >>> >>> I am a newbie with Xeno. My goal for the beginning of 2007 is to laun= ch >>> a project for 4 french studiants : a box with Linux embedded and a us= b >>> camera. The embedded application will analyse the movies in Real time= >>> and lead a mobile machine with CAN-BUS. >>> Now i play with Xeno for my knowledge (without specific hardware) : = a >>> little linux installed in a usb key with a little embedded distrib >>> >>> - vanilla kernel 2.6.16 with patch for usb [.config is joint] >>> - Xenomai 2.1.2 >>> - essentially BusyBox >>> - for xenomai : only "latency" directory and libs in usr/libs >>> I have checked "SMI woraround" for the kernel. >>> In BIOS I have UNchecked "legacy usb". >>> >>> >>> my Desktop PC (a AMD ATHLON) can boot with this little vanilla kernel= >>> and >>> 1/ a little embedded distrib of my own >>> >>> OR >>> >>> 2/ a complete mandrake 9.1 on a partition of a classic hard disk >>> >>> I have 2 differents problems when I lauch this : >>> >>> 1/ with the linux embedded directories on the usb key >>> high latency > 100 us are ok ? perhaps usb work is not compatible >>> with RT ? >>> =20 >> >> Try loading the standard USB drivers (at least uhci_hcd) if they aren'= t >> yet. Actually, I've seen boxes (granted, they were far older) where I >> had to switch legacy USB *on* to avoid disturbances. In any case, chec= k >> carefully if you followed all tips in TROUBLESHOOTING regarding latenc= y >> issues (APM, ACPI, etc.). >> >> =20 >>> 2/ with the complete mandrake 9.1 : >>> it crashes X after 1 or few minutes. >>> What is the relation between X and Xenomai ? >>> Is Xenomai compatible with X ? >>> =20 >> >> Yes, as long as X is not playing against us, e.g. by hard-disabling >> interrupts or doing (too) evil things on the buses. Any non-GPL driver= >> in this game here (NVidia&Co)? Better avoid this. Also try to disable >> accelerated mode in your X setup to see if things improve. >> >> Jan >> >> =20 > Ok , for the box with a vanilla kernel I will try the differents > possibilities. Actually i disable > a max of things ... >=20 > For the box with X : the big surprise was : very goods latencies > (comparativeley with no X !!) > Why ???? > (Before crashing) If it turns out to be an ACPI/APM issue, X may keep your box busier than plain text mode, thus avoid those latency peaks by keeping it out of certain sleep modes - well, an attempt to explain something I can't with the currently available information... >=20 > for crashing > I 'll verify theses 2 points : > nvidia driver > accelerated mode : Is it a x server setup ? >=20 See Gilles' reply =3D> XF86Config. Jan PS: Don't forget to reply-to-all. --------------enig0A8F44C518900091F0949246 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFFUf35niDOoMHTA+kRAlE0AJ9TbaB3AgLC7rn+vw5U8ylxQYgougCfWEmE vhbhBS8eDbLqtH7UH0cCPmY= =AxfB -----END PGP SIGNATURE----- --------------enig0A8F44C518900091F0949246--