I finally had a bit of time to try out different kernel versions to find

 out where this began... and it's in 2.6.24-git2.
What happens: Oracle 11g starts up and forks a number of so

 called background processes. Starting in  2.6.24-git2 the VKTM

 process never fully completes its initialization but gets in R state,

 never accumulating CPU, and can't be straced/gdb'd/killed.
Sysrq-T reports for VKTM looks like this
Feb  9 16:10:46 sandman kernel:  =======================

Feb  9 16:10:46 sandman kernel: oracle        R running   2684  2258      1

Feb  9 16:10:46 sandman kernel:        f591dfb0 00200086 f6bbc3c4

f6863cc0 c010547a 00000000 b794f62c b7b70600

Feb  9 16:10:46 sandman kernel:        b79453dc f591d000 c0103caa

b794f62c b7943708 b79453e4 b7b70600 b79453dc

Feb  9 16:10:46 sandman kernel:        bfb0dd5c b79500b0 0000007b

0000007b c0320000 ffffffff 0e072d7a 00000073

Feb  9 16:10:46 sandman kernel: Call Trace:

Feb  9 16:10:46 sandman kernel:  [<c010547a>] ? do_IRQ+0xac/0xc1

Feb  9 16:10:46 sandman kernel:  [<c0103caa>] work_resched+0x5/0x16

Feb  9 16:10:46 sandman kernel:  [<c0320000>] ? pci_setup+0xb3/0x104

Feb  9 16:10:46 sandman kernel:  =======================
2.6.24-git1 is okay

2.6.24-git2 is bad

...

2.6.24-git20 is bad
Only differences in kernel .config between -git1 and -git2 are
[asuardi@sandman src]$ diff .config-2.6.24-git[12]

3,4c3,4

< # Linux kernel version: 2.6.24-git1

< # Sat Jan 26 01:04:43 2008
Symptom is similar to what Rafael reported here
  http://www.ussg.iu.edu/hypermail/linux/kernel/0801.3/4114.html
 and similarly VKTM attempts to run at elevated priority as normal

 user process (Oracle kernel binary is not setuid root).
Peter Zijlstra's patches mentioned in the above thread, at
 http://programming.kicks-ass.net/kernel-patches/sched-rt-group ,
 do not appear to be in -git20 yet.
I'm available for further testing. Thanks, ciao,
--alessandro
 "We act as though comfort and luxury were the chi...
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