I supposed it, but I've not seen 7.3.
A small patch for low performance on NUMA arquitectures could be the chance
of using more than one shared region.
Several months away there was a brief talk about low performance on IRIX, it
was not real, it's low performance on Origin servers, they use ccNUMA
architecture, so using a single shared segment allocated by only one
proccess doesn't give IRIX planner a chance for attempting to optimize
memory accesses, even thought page migration is almost impossible with DB
memory accesses.
With this scenario, IRIX uses a first-touch algorith for memory placement
(all the memory is allocated on the node Postgres starts running). Due to
high latency between local and remote memory accesses, if there is data
modification, remote proccesors cache hit rate goes down, all of this makes
that all the basis of high scalability on this systems(big cache, memory
distribution, increasing bandwith and page migration) ar thrown to the
earth.
I suppose that making more than one shared segment it's not too difficult,
but with this u can do that a long time Postgres running on a NUMA system
achieve a good performance scenario.
Is it so difficult?
Thanks and regards.
Luis Amigo
