Re: CheckpointStartLock starvation

Heikki Linnakangas <heikki@enterprisedb.com> wrote:

> It looks like the bgwriter gets starved waiting on the 
> CheckpointStartLock. The CheckpointStartLock is held in shared mode over 
> an XLogFlush when committing, which on an extremely busy system like a 
> benchmark is always long enough to have a new transaction to acquire the 
> CheckpointStartLock again.

If the starvation comes from giving unfair priorities on shared locks
against exclusive locks, does the below TODO item help us?

| Locking
| Fix priority ordering of read and write light-weight locks (Neil) 
| http://archives.postgresql.org/pgsql-hackers/2004-11/msg00893.php
| http://archives.postgresql.org/pgsql-hackers/2004-11/msg00905.php 

Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center