On Sun, Feb 19, 2012 at 8:15 PM, Robert Haas <robertmh...@gmail.com> wrote: > On Sun, Feb 19, 2012 at 1:53 PM, Simon Riggs <si...@2ndquadrant.com> wrote: >> Recent changes for power reduction mean that we now issue a wakeup >> call to the bgwriter every time we set a hint bit. >> >> However cheap that is, its still overkill. >> >> My proposal is that we wakeup the bgwriter whenever a backend is >> forced to write a dirty buffer, a job the bgwriter should have been >> doing. >> >> This significantly reduces the number of wakeup calls and allows the >> bgwriter to stay asleep even when very light traffic happens, which is >> good because the bgwriter is often the last process to sleep. >> >> Seems useful to have an explicit discussion on this point, especially >> in view of recent performance results. > > I don't see what this has to do with recent performance results, so > please elaborate. Off-hand, I don't see any point in getting cheap. > It seems far more important to me that the background writer become > active when needed than that we save some trivial amount of power by > waiting longer before activating it.
Then you misunderstand, since I am advocating waking it when needed. -- Simon Riggs 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
