From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4DD3EAAF.2010902@domain.hid> Date: Wed, 18 May 2011 17:50:07 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <294B28951EBE8146839AF99A61CB5FCE6B3F1A7999@domain.hid> <4DCD0DFC.7050506@domain.hid> <294B28951EBE8146839AF99A61CB5FCE6B3F1A7DDD@SI-MBX17.de.bosch.com> <4DD25DF5.1070609@domain.hid> <294B28951EBE8146839AF99A61CB5FCE6B3FF1946E@SI-MBX17.de.bosch.com> In-Reply-To: <294B28951EBE8146839AF99A61CB5FCE6B3FF1946E@SI-MBX17.de.bosch.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai-help] Same problems with ipipe-2.6.37-x86-branch and xenoami-head.git on Core 2 Duo E8400 - fixed with CONFIG_HPET_TIMER disabled List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Benner Bernd (MH/EES)" Cc: "xenomai@xenomai.org" On 2011-05-18 17:40, Benner Bernd (MH/EES) wrote: > Hello, > > I have rebuild my Kernel 2.6.37.6-x86 and uses xenomai-head.git. ( is this xenomai-2.6 git ? ) > This version has the same problems on the Core 2 Duo E8400 machines. > > But there are some strange kernel messages on startup: > > May 18 16:07:33 (none) user.warn kernel: CE: hpet3 increased min_delta_ns to 7500 nsec > May 18 16:07:33 (none) user.warn kernel: CE: hpet3 increased min_delta_ns to 11250 nsec > May 18 16:07:33 (none) user.warn kernel: hrtimer: interrupt took 5978 ns > ... > May 18 16:07:33 (none) user.warn kernel: CE: hpet2 increased min_delta_ns to 11250 nsec > ... > after a start of latency ( via ssh ) the linux domain will slow down and the sata driver will come in trouble. > > > If I rebuild my Kernel with CONFIG_HPET_TIMER disabled, latency will run normally on the Core 2 Duo E8400 machines. > > CONFIG_HPET_TIMER has to be disabled on faster Core 2 Duo machines! There must be a consistency problem! ( probably in > io_apic- handling with CONFIG_HPET_TIMER enabled ) > > I will rebuild and test my kernel with stable 2.5.X xenomai versions and ADEOS patches with CONFIG_HPET_TIMER disabled! Ah! I bet you have >3 HPET timers, and they are MSI capable. In that case, Linux will actually prefer them over the LAPIC as clockevent device, and Xenomai breaks apart. I didn't discovered this as my test "machine" (QEMU/KVM) requires extra switches to enable that scenario. However, it's getting more and more common on modern hardware, we should take some measures to catch this conflict. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux