On Tue, Feb 15, 2011 at 20:01, Scott Marlowe <scott.marl...@gmail.com> wrote: > run htop and look for red. if youi've got lots of red bar on each CPU > but no io wait then it's waiting for memory access.
I don't think this is true. AFAICT the red bar refers to "system time", time that's spent in the kernel -- either in syscalls or kernel background threads. Operating systems don't generally account memory accesses (cache misses) for processes, if you don't specially ask for it. The closest thing I know of is using Linux perf tools, e.g. "perf top -e cache-misses". OProfile, DTrace and SystemTap can probably do something similar. Regards, Marti -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
