From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <44C25DB0.50601@domain.hid> Date: Sat, 22 Jul 2006 19:17:36 +0200 From: Jan Kiszka MIME-Version: 1.0 Subject: Re: [Xenomai-help] Beginner's question / testsuite / latency References: <442248c90607201417m24729b7cs23a8b82b719ff1cc@domain.hid> <44BFFC73.9080603@domain.hid> <200607221152.34298.bidsonux@domain.hid> In-Reply-To: <200607221152.34298.bidsonux@domain.hid> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigD8EDFBD067F57FD5C9887C55" 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: Julien Heyman Cc: xenomai@xenomai.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigD8EDFBD067F57FD5C9887C55 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Julien Heyman wrote: > Hi, >=20 > On Thursday 20 July 2006 23:58, Jan Kiszka wrote: >> Julien Heyman wrote: >>> Hi, >>> >>> I am currently trying to evaluate Xenomai, and my current setup is : >>> VIA C3 533Mhz processor, Kubuntu 6.06 Linux distribution. >>> I am using Xenomai-2.1.0 over a 2.6.17.4 kernel. >> General advice: especially when starting new, try to pick the latest >> version, at least the latest from the preferred series (here 2.1.2). B= ut >> 2.2 is even better. :) >> >=20 > OK. Actually started with Xenomai-2.1.0 then switched to 2.1.1 to fix a= kernel=20 > build error. But anyway, I will start with a fresh install of 2.2 as so= on as=20 > I have figured out the other points :) >=20 >>> When I run the latency part of the testsuite (in a console under KDE)= , I >>> get >>> results that I cannot understand, so I probably did something wrong >>> (execution trace included below). >>> I get reasonable values during the first seconds, then all of a sudde= n >>> latencies begin to rise, continuously, to very large values. >>> - I did check that DMA transfer is activated on my HD. >>> - I did select "Enable SMI workaround" + "Globally disable SMI" in th= e >>> Xenomai >>> options while configuring the kernel. >>> - I have disabled power management at BIOS level and disabled ACPI >>> support and >>> CPU frequency scaling during kernel configuration. >>> - I checked that I don't have anything called "legacy USB" in my BIOS= =2E I >>> do have an "OnChip USB" option enable in the BIOS though. >>> >>> Any advice would be appreciated ! >> Maybe it's related to some other weird on-chip hardware. At work we ru= n >> Xenomai only on a head-less VIA C3 box, i.e. without X. No problems so= >> far. I would suggest to try stopping X and run the test from the text = mode. >=20 > This is interesting : indeed when I switch to console mode (Ctrl+Atl+F1= ) and=20 > run the test, the latency values stay right on track. > If I let the test run, switch to X, and switch back to the original con= sole,=20 > the values have gone wild in the meantime. > So there seems to be a strong link with X.=20 > What does that say about potential causes of my issue ? Don't know. Might be a weird hardware design (wrt bus latencies) - or do you use any binary-only driver for X? >=20 >> A further tool to analyse such effects in details is the I-pipe tracer= =2E >> It's an additional patch you have to apply to your kernel (see >> http://download.gna.org/adeos/patches/v2.6/i386/tracer). Enable this >> I-pipe option, rebuild your kernel, and start the latency test with -f= =2E >> The test will then capture on every new worst-case delay a backtrace t= o >> /proc/ipipe/trace/frozen. You may want to play with the number of >> back-trace points or the verbose mode (see /proc/ipipe/trace/*) even >> after the capturing. >> >=20 > I had already used an adeos patch during my initial kernel-patching > (adeos-ipipe-2.6.17-i386-1.3-07.patch) The tracer is an additional patch on top of I-pipe, see link above. > I tried running the latency test using /usr/xenomai/bin/xeno-load laten= cy -f > but I get this error : >=20 > =3D=3D Sampling period: 100 us > =3D=3D Test mode: periodic user-mode task > =3D=3D All results in microseconds > latency: failed to open benchmark device, code -19 > (modprobe xeno_timerbench?) >=20 > What am I doing wrong ? For < 2.2: check if CONFIG_XENO_DRIVERS_TIMERBENCH is y or m. If it's a module, follow the suggestion latency printed. In 2.2 the required tracing interface was moved to the nucleus, no need for these steps then. Jan --------------enigD8EDFBD067F57FD5C9887C55 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 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iD8DBQFEwl2wniDOoMHTA+kRAsmLAJ0Vbf6yqxr1k3DDEutepkvId0Xi3ACeLCGX 0gZAo1YB0d0bGoxtm6+jFEo= =aQca -----END PGP SIGNATURE----- --------------enigD8EDFBD067F57FD5C9887C55--