On Wed, Sep 18, 2013 at 10:30 AM, Lonni J Friedman <netll...@gmail.com>wrote:
> > > > > This looks similar to cases I've seen of THP defrag going wild. > > Did the OS version or configuration change? Did the PostgreSQL > > memory settings (like shared_buffers) change? > > I think you're onto something here with respect to THP defrag going > wild. I set /sys/kernel/mm/transparent_hugepage/defrag to 'never' and > immediately the load dropped on both slaves from over 5.00 to under > 1.00. > > So this raises the question, is this a kernel bug, or is there some > other solution to the problem? > Also, seems weird that the problem didn't happen until I switched from > 9.2 to 9.3. Is it possible this is somehow related to the change from > using SysV shared memory to using Posix shared memory and mmap for > memory management? > I would guess that it is probably a kernel bug which gets efficiently exercised by the SysV to Posix change. Cheers, Jeff
