Disable WAL completely - Performance and Persistency research

Hi All,

As part of my masters at TAU, I'm currently conducting some research
regarding new persistent memory technology.
I'm using PG for this research and would like to better understand some of
the performance bottlenecks.
For this reason I'm trying to disable the WAL completely, using some hacks
on the source code and compiling my own version.

So what I'm actually looking for, is some guidance about a simple way to:

1. Disable the WAL by not writing anything to the xlog directory. I don't
care about recovery/fault tolerance or PITR/ replication etc at the moment.
I'm aware that the WAL and checkpoint are bind in many ways and are crucial
for PG core features.
I tried changing the status of all tables to "unlogged" tables by changing
RelationNeedsWAL MACRO, as well as "needs_wal" parameter at storage.c.
But, got no performance benefit, so I guess this was the wrong place to
change.

2. Cancel the locking around WAL files - I don't care about corrupted
files at the moment, I just want to see what is the maximum performance
benefit that I can get without lock contention.

Any guidance on how to do so would be appreciated :)

Kind regards,
Netanel