how to change the default size of hash table?

[hewt@xxxxxxxxxx (He Weitao)]

Hi, all

I encountered a question about the size of hash table:

LVS_2.2.13-HOWTO said:
"The hash table is used to speed up the connection lookup. The connection
entry is used keep state so that packets belongs to a connection from
the client will be sent to the server previously allocated for the
connection. The default number of connections (== number of entries
in hash table) is 2^12. This can be configured when building the kernel
Makefile."

    I find some files about this:
include/net/ip_vs.h
net/ipv4/ip_masq.c
net/ipv4/ip_vs.c
  but  I cannot find '2^12' and where can I change this parameter.

Suppose there are 6000 connections to Director at the same time, 
and the ppc is default 360s,  what should this parameter be set to ?
and what is the upper limit of this parameter? 2^18?

thanks again.

ttao.