How to install pg_prewarm?

Hi,

Refer to
Relational Database Technologies: Caching in PostgreSQL.

I would like to install pg_prewarm.
According to the above site, I need to apply pg_prewarm patch on my PG source installation, which can be :


Untar location of PG source : /usr/local/src/postgresql-9.1.3
PG installation locatin : /usr/local/pgsql91
All downloads Location : /usr/local/src


However I am unable to find the sources as I installed using rpm.

Below the output when running patch:
=============================
postgres@database:~> pwd
/var/lib/pgsql
postgres@database:~> patch -p1 < pg_prewarm_v2.patch
can't find file to patch at input line 5
Perhaps you used the wrong -p or --strip option?
The text leading up to this was:
--------------------------
|diff --git a/contrib/Makefile b/contrib/Makefile
|index d230451..036f4fa 100644
|--- a/contrib/Makefile
|+++ b/contrib/Makefile
--------------------------
File to patch: pg_prewarm_v2.patch
patching file pg_prewarm_v2.patch
Hunk #1 FAILED at 32.
1 out of 1 hunk FAILED -- saving rejects to file pg_prewarm_v2.patch.rej
patching file contrib/pg_prewarm/Makefile
patching file contrib/pg_prewarm/pg_prewarm--1.0.sql
patching file contrib/pg_prewarm/pg_prewarm.c
patching file contrib/pg_prewarm/pg_prewarm.control
can't find file to patch at input line 280
Perhaps you used the wrong -p or --strip option?
The text leading up to this was:
--------------------------
|diff --git a/doc/src/sgml/contrib.sgml b/doc/src/sgml/contrib.sgml
|index 97031dd..80191bb 100644
|--- a/doc/src/sgml/contrib.sgml
|+++ b/doc/src/sgml/contrib.sgml
--------------------------


===========================

Anyone ? Please guide.

Regards,
Eye Gee