936457419d
c4d5cb71d2 adjusted the fast-path locking code to allow some configuration of the number of fast-path locking slots via the max_locks_per_transaction GUC. In that commit the FAST_PATH_REL_GROUP() macro used integer division to determine the fast-path locking group slot to use for the lock. The divisor in this case is always a power-of-two value. Here we swap out the divide by a bitwise-AND, which is a significantly faster operation to perform. In passing, adjust the code that's setting FastPathLockGroupsPerBackend so that it's more clear that the value being set is a power-of-two. Also, adjust some comments in the area which contained some magic numbers. It seems better to justify the 1024 upper limit in the location where the #define is made instead of where it is used. Author: David Rowley <drowleyml@gmail.com> Reviewed-by: Tomas Vondra <tomas@vondra.me> Discussion: https://postgr.es/m/CAApHDvodr3bcnpxcs7+k-3cFwYR0tP-BYhyd2PpDhe-bCx9i=g@mail.gmail.com
PostgreSQL Database Management System
This directory contains the source code distribution of the PostgreSQL database management system.
PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings.
Copyright and license information can be found in the file COPYRIGHT.
General documentation about this version of PostgreSQL can be found at https://www.postgresql.org/docs/devel/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/devel/installation.html.
The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.