From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4624D71E.3040008@domain.hid> Date: Tue, 17 Apr 2007 16:18:06 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <5C40CD1E4697424ABDE3AC57CF1B22C603221037@domain.hid> In-Reply-To: <5C40CD1E4697424ABDE3AC57CF1B22C603221037@domain.hid> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigFA327C38E917FD6E639BDBD2" Sender: jan.kiszka@domain.hid Subject: Re: [Xenomai-help] Perfs and rt alarms questions. List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "RAKOTOSALAMA, Nirilanto" Cc: xenomai@xenomai.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigFA327C38E917FD6E639BDBD2 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable RAKOTOSALAMA, Nirilanto wrote: > Hello everybody. >=20 > I managed to compile a stable kernel (the Scalability O(1) scheduler op= tions seems to make my system freeze) That's not good. What precisely did you do? Applied the .config you posted, just enabling CONFIG_XENO_OPT_SCALABLE_SCHED? And what test case, latency? > xenomai 2.3.1 and vanilla 2.6.20.4, gcc 4.1.1 on FC6. >=20 > I'm programming and testing a xenomai support for a timer library using= rt_alarm. The test program > lauches the timer periodically and calculate the precision (difference = between theoretical and practical results). >=20 > When I launch the latency test, the max latency I have doesn't exceed 1= 0us. So I supposed the precision shouldn't=20 Using what load for the system? Keep in mind that unloaded benchmark numbers are practically meaningless. > exceed 10 to 20us as well, No ? But sometimes, the precision exceed 30 = to 60us. Is it normal ? Depending on your hardware (CPU, chipset, peripherals), this can be very well a worst-case latency of the loaded system. Try to capture such a result with the tracer (you may put your own xntrace_user_freeze() calls into your timer lib). > Something wrong in the way I use rt alarms ? in the kernel configuratio= n ? >=20 > I attach :=20 > - .config > - tests results with overtime with this actual config > - tests results without overtime I had with an old config (unfortunate= ly I cannot restore it). The precision was less than=20 > 8us, I didn't enable xeno debug option. I haven't managed to get such= high precision since I recompiled my kernel. > - test program test_stability_trace.c > - xenomai timer library support implementation support_xenomai.c >=20 > Thanks in advance. >=20 > Niry. >=20 Jan --------------enigFA327C38E917FD6E639BDBD2 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFGJNcjniDOoMHTA+kRAmf3AJ46yVh7dNXWFUkwjc45cC93b5sVFgCfRWYu i3IpyghMaWLJMlG+FySSNts= =jy74 -----END PGP SIGNATURE----- --------------enigFA327C38E917FD6E639BDBD2--