Messages in this thread | | | Date | Sun, 19 Nov 2006 15:42:42 +0100 | From | Robert Schwebel <> | Subject | Re: 2.6.19-rc6-rt4, changed yum repository |
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Ingo,
On Sat, Nov 18, 2006 at 05:30:32PM +0100, Ingo Molnar wrote: > i've released the 2.6.18-rc6-rt4 tree, which can be downloaded from > the usual place:
I have problems runinng cyclictest on later -rt kernels, up to -rt4.
This is a Dell Latitude D610, with Pentium M & ICH6 chipset.
Symptoms:
- "cyclictest -n -p 90 -t 4" is just "running upwards"
With 2.6.18-rt5 it looked like this, much better:
isonoe:/home/rsc/tmp/rtpreempt/cyclictest-0.11# ./cyclictest -n -t 4 -p 90 -l 1000 1.51 0.99 0.41 1/117 9885
T: 0 ( 9802) P:90 I: 1000 C: 1000 Min: 7 Act: 11 Avg: 16 Max: 561 T: 1 ( 9803) P:89 I: 1500 C: 671 Min: 7 Act: 11 Avg: 15 Max: 498 T: 2 ( 9804) P:88 I: 2000 C: 504 Min: 7 Act: 11 Avg: 16 Max: 533 T: 3 ( 9805) P:87 I: 2500 C: 403 Min: 6 Act: 11 Avg: 13 Max: 394
- Using a relative timer (-r), I get huge latencies:
isonoe:/home/rsc/tmp/rtpreempt/cyclictest-0.11# ./cyclictest -n -p 90 -t 4 -r -l 1000 0.47 0.76 0.61 3/128 16112
T: 0 (15901) P:90 I: 1000 C: 1000 Min: 2963 Act: 2990 Avg: 4334 Max: 7039 T: 1 (15902) P:89 I: 1500 C: 667 Min: 4003 Act: 6495 Avg: 6492 Max: 6541 T: 2 (15903) P:88 I: 2000 C: 667 Min: 3498 Act: 5995 Avg: 5993 Max: 6041 T: 3 (15904) P:87 I: 2500 C: 667 Min: 5433 Act: 5488 Avg: 5498 Max: 6898
This is with "lapic lapictimer" on the kernel commandline. I've manually switched the clocksource from pit to tsc:
isonoe:/sys/devices/system/clocksource/clocksource0# cat available_clocksource jiffies tsc pit isonoe:/sys/devices/system/clocksource/clocksource0# cat current_clocksource tsc
Some related dmesg output:
Kernel command line: root=/dev/sda7 ro lapic lapictimer Found and enabled local APIC! mapped APIC to ffffd000 (fee00000) ... WARNING: experimental RCU implementation. Clock event device pit configured with caps set: 07 ... Clock event device pit new caps set: 03 Clock event device lapic configured with caps set: 04 ... Time: pit clocksource has been installed. ... ***************************************************************************** * * * REMINDER, the following debugging options are turned on in your .config: * * * * CONFIG_CRITICAL_PREEMPT_TIMING * * CONFIG_CRITICAL_IRQSOFF_TIMING * * CONFIG_FUNCTION_TRACE * * * * they may increase runtime overhead and latencies. * * * *****************************************************************************
Last time this machine worked was with 2.6.18-rt5, 2.6.18-rt7 didn't work any more. If it is helpful, I can do some further boot tests to find out which patch broke it.
Robert -- Dipl.-Ing. Robert Schwebel | http://www.pengutronix.de Pengutronix - Linux Solutions for Science and Industry Handelsregister: Amtsgericht Hildesheim, HRA 2686 Hannoversche Str. 2, 31134 Hildesheim, Germany Phone: +49-5121-206917-0 | Fax: +49-5121-206917-9
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