Hi Nilesh.

Using reply all this time...

On Thu, Jan 6, 2011 at 10:27 PM, Tayade, Nilesh
[off-list ref] wrote:
...snip...

quoted

You shouldn't be holding  a spinlock for periods of time approaching
the length of a timeslice. The timer interrupt is what determines the
end of a timeslice. No timer interrupt, no end of a timeslice.
Preemption is also triggered by the timer interrupt, or by releasing a
resource that a higher priority task is waiting for.

May be my understanding is incorrect, but wouldn't we hit the NMI watchdog here(assuming we are running on x86/x86_64)?
We have a system lockup for long time.
http://lxr.linux.no/#linux+v2.6.37/Documentation/nmi_watchdog.txt

Could someone please clarify?

Did you enable it by passing in nmi_watchdog=1 on the kernel command
line? (and verify that it was working fine - as described in the
nmi__watchdog.txt file)

Dave Hylands