From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4551FE90.2040808@domain.hid> Date: Wed, 08 Nov 2006 16:58:08 +0100 From: Jean-Luc Pamart 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> <4551FDF9.1070401@domain.hid> In-Reply-To: <4551FDF9.1070401@domain.hid> Content-Type: text/plain; charset="iso-8859-15"; format="flowed" Content-Transfer-Encoding: quoted-printable List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: xenomai-help Jan Kiszka a =E9crit : > Jean-Luc Pamart wrote: > =20 >> Jan Kiszka a =E9crit : >> =20 >>> Jean-Luc Pamart wrote: >>> =20 >>> =20 >>>> Hello >>>> >>>> I am a newbie with Xeno. My goal for the beginning of 2007 is to launch >>>> a project for 4 french studiants : a box with Linux embedded and a usb >>>> 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 >>>> =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, check >>> carefully if you followed all tips in TROUBLESHOOTING regarding latency >>> issues (APM, ACPI, etc.). >>> >>> =20 >>> =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 >>>> =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 >>> =20 >> Ok , for the box with a vanilla kernel I will try the differents >> possibilities. Actually i disable >> a max of things ... >> >> For the box with X : the big surprise was : very goods latencies >> (comparativeley with no X !!) >> Why ???? >> (Before crashing) >> =20 > > 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. > > =20 OK ! =09 =09 =09 ___________________________________________________________________________= =20 Yahoo! Mail r=E9invente le mail ! D=E9couvrez le nouveau Yahoo! Mail et son= interface r=E9volutionnaire. http://fr.mail.yahoo.com