Red Hat Bugzilla – Bug 121383
Severe time drift with SMP kernel
Last modified: 2007-11-30 17:10:40 EST
From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040211 Firefox/0.8 Description of problem: When using the SMP kernel on a Pentium 4 HT machine, a severe time drift around 1/2 hour per day happens. The drift increases significantly when running any application that uses alsa, to around 5-10 minutes per hour. In both cases the clock runs faster than normal. This drift does not happen with the UP kernel. Version-Release number of selected component (if applicable): at least kernel-smp-2.6.4-1.300 to kernel-smp-2.6.5-1.332 How reproducible: Always Steps to Reproduce: 1. Boot with SMP kernel 2. Do nothing or run any program. 3. Using programs that require ALSA increases drift. Actual Results: Drift is quickly apparent by comparing the clock with an accurate clock. Expected Results: Clock should be accurate withing milliseconds, as it happens with the UP kernel. Additional info: This problem did not occur with the 2.4 kernels, both UP and SMP. Machine is a Sager 5690 notebook, Pentium 4 HT 3.2 GHz, Intel i865PE+ICH5 chipset, Intel 82801EB/ER AC'97 audio.
Does the option "acpi=off" make a difference here. Also can you attach your boot up log of the problem system.
Could well be a victim of the HZ=1000 stuff in 2.6 Are you running ntp ?
Created attachment 99924 [details] Default SMP boot log.
Created attachment 99925 [details] Default SMP boot log. When I boot the machine with acpi=off, the kernel starts to boot, then it prints the following messages: ACPI: ACPI tables contain no PCI IRQ routing entries PCI: Invalid ACPI-PCI IRQ routing table and then it hard locks. If I pass the option noapic to the kernel, it seems to work fine. I haven't tried pci=noapic, which is an option I saw in an LKML email. The situation happens regardless of whether I use NTP or not.