Re: High SYS CPU - need advise

yeah.  ok, nest steps:
*) can you confirm that postgres process is using high cpu (according
to top) during stall time

*) if, so, please strace that process and save some of the log

*) you're using a 'bleeding edge' kernel.  so we must be suspicious of
a regression there, particularly in the scheduler.

*) I am suspicious of spinlock issue. so, if we can't isolate the
problem, is running a hand complied postgres a possibility (for lock
stats)?

*) what is the output of this:
echo /proc/sys/vm/zone_reclaim_mode