I was hoping to use the TSC for clocksource since I've read on here that not having interrupts going off every millisecond for the clock would be a performance savings. I'm running an updated kernel 3.7.6 on fedora 17
I'm running the latest 6501 BIOS (rev 1.41c that makes CPU run at 1600 mhz) [root@soekris-6501 ~]# uname -a Linux soekris-6501 3.7.6-102.fc17.i686.PAE #1 SMP Mon Feb 4 17:46:36 UTC 2013 i686 i686 i386 GNU/Linux I'm using these additions on kernel cmdline: pcie_aspm=off intel_idle.max_cstate=1 dmesg | egrep -i clock [ 0.275344] Switching to clocksource refined-jiffies [ 1.730903] rtc_cmos rtc_cmos: setting system clock to 2013-02-25 16:42:52 UTC (1361810572) [ 1.731799] p4-clockmod: Warning: EST-capable CPU detected. The acpi-cpufreq module offers voltage scaling in addition to frequency scaling. You should use that instead of p4-clockmod, if possible. [ 2.115743] Switching to clocksource tsc [ 3.762410] Clocksource tsc unstable (delta = 75920774 ns) [ 3.768036] Switching to clocksource refined-jiffies With the intel_idle.max_cstate=1 it will allow the tsc to be considered and it uses it for a bit, then declares it unstable and switches to jiffies [root@soekris-6501 ~]# cat /proc/interrupts | egrep timer ; sleep 1; cat /proc/interrupts | egrep timer 0: 480637 0 IO-APIC-edge timer LOC: 1130 482017 Local timer interrupts 0: 481645 0 IO-APIC-edge timer LOC: 1130 483025 Local timer interrupts You can see from above I'm getting 1000 timer interrupts per second on one of the CPU cores. One last tip for those running linux on the 6501 -- I blacklisted kernel module pch_gbe because it was causing a slew of MII errors when it tries to load. I think the modules for pch_gbe thinks there's an "internal" intel pch gig-e adapter in this system when there isn't -- it obviously uses the 82574L x 4. So not loading this module gets rid of these annoying errors some of you may have in dmesg: [ 1.490801] pch_gbe: pch-gbe.miim won't go Ready [ 1.492377] pch_gbe: pch-gbe.miim won't go Ready [ 1.492377] pch_gbe: pch-gbe.miim won't go Ready [ 1.492377] pch_gbe: pch-gbe.miim won't go Ready [ 1.492377] pch_gbe: pch-gbe.miim won't go Ready I simply added: blacklist pch_gbe to my /etc/modprobe.d/blacklist.conf to hush those annoying messages on my 6501. Hope this helps someone else searching for the same solution. Thanks for any info on how to get my TSC to be stable so it can be the clocksource... -Eric Malkowski _______________________________________________ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
