On Sunday, November 18, 2012 03:07:01 AM Jeff Davis wrote: > Process A (process that clears a VM bit for a data page): > 1. Acquires exclusive lock on data buffer > 2. Acquires exclusive lock on VM buffer > 3. clears VM bit > 4. Releases VM buffer lock > 5. Releases data buffer lock
Well, but right this is a rather big difference. If vm pages get unconditionally locked all the time we will have a huge source of new contention as they are shared between so many heap pages. Andres -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
