Consistent failures in rt/tst-cpuclock2 ?

[ppluzhnikov at google dot com (Paul Pluzhnikov)]

Greetings,

I am seeing a consistent failure of rt/tst-cpuclock2 on my x86_64 machine
running Linux 2.6.38.

The failure is present in both glibc-2.11, and current git trunk, and
looks like this:

live thread clock fffffffffffea47e resolution 0.000000001
live thread before sleep => 0.000134956
self thread before sleep => 0.000334472
live thread after sleep => 0.498723872
self thread after sleep => 0.000364129
process before - after 493144979 outside reasonable range (498588916)

As far as I can tell, glibc is not accepting process clock having
accumulated less time than the chew_cpu thread clock.

If this really is a problem, it would seem to be a kernel one.

Do others see this failure? Is my kernel really broken, or is glibc making
un-warranted assumptions in this test?

My system has 12 of these:

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 44
model name      : Intel(R) Xeon(R) CPU           X5650  @ 2.67GHz
stepping        : 2
cpu MHz         : 1596.000
cache size      : 12288 KB
physical id     : 0
siblings        : 12
core id         : 0
cpu cores       : 6
apicid          : 0
initial apicid  : 0
fpu             : yes
fpu_exception   : yes
cpuid level     : 11
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr pdcm dca sse4_1 sse4_2 popcnt aes lahf_lm ida arat epb dts tpr_shadow vnmi flexpriority ept vpid
bogomips        : 5333.52
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management:

Thanks,
--
Paul Pluzhnikov