Re: sinval contention reduction

Simon Riggs <simon@2ndquadrant.com> writes:
> Patch to reduce the contention on SInvalLock, as discussed here:
> http://archives.postgresql.org/pgsql-hackers/2007-09/msg00501.php
> and
> http://archives.postgresql.org/pgsql-performance/2008-01/msg00023.php

> For discussion.

This seems large, complex, and untested (I note in particular a
guaranteed-to-fail Assert).  I'm also wondering if it will help much,
since unless the system is already in trouble, the normal case will be
that all backends have absorbed all messages and so they'll all see
stateP->nextMsgNum == segP->minMsgNum when they first respond to a
signal.  Do you have any evidence for performance improvement?

            regards, tom lane