On larger Linux machines, we have been running with spin locks replaced by
generic posix mutexes for years now. I personally haven't look at the code for
ages, but we maintain a patch which pretty much does the same thing still:
Ref: http://www.postgresql.org/message-id/4FEDE0BF.7080203@schokola.de
I understand that there are systems out there which have less efficient posix
mutex implementations than Linux (which uses futexes), but I think it would
still be worth considering to do away with the roll-your-own spinlocks on
systems whose posix mutexes are known to behave.
Nils
