Re: [RFC] don't copy the whole table to all the other CPUs

[Rick Jones <rick.jones2@hp.com>]

Changli Gao wrote:
> When reviewing the iptables code, I find there is one exact copy of
> table on every possible CPU for parallel processing. However, only
> counters are private, and the others are the same. It is a wast of
> memory. I know the current implementation maybe good for NUMA, but I
> don't think NUMA is common, and I doubt its benefit. I'll try to
> convert the code use one shared table, but private counters.
> 
> Any comment?

Others have already commented on how the code is changing and whether or not 
what is done is necessary for good performance in the face of NUMA, but I wanted 
to point-out that NUMA is quite common.  Just in the x86 space, virtually 
anything with two or more sockets sold starting with Nehalem-EP (?) is a NUMA 
system, and one can go farther back than that when one goes to Barcelona. 
Per-processor memory controllers and more than one processor implies NUMA.

rick jones