Re: [HACKERS] Reducing bgwriter wakeups

2012-03-02 Thread Heikki Linnakangas
On 20.02.2012 00:18, Robert Haas wrote: On Sun, Feb 19, 2012 at 4:11 PM, Simon Riggs wrote: On Sun, Feb 19, 2012 at 8:15 PM, Robert Haas wrote: On Sun, Feb 19, 2012 at 1:53 PM, Simon Riggs wrote: Recent changes for power reduction mean that we now issue a wakeup call to the bgwriter every t

Re: [HACKERS] Reducing bgwriter wakeups

2012-02-19 Thread Robert Haas
On Sun, Feb 19, 2012 at 5:56 PM, Jeff Janes wrote: > Would the log really have been archived in 9.1?  I don't think > checkpoint_timeout caused a log switch, just a checkpoint which could > happily be in the same file as the previous checkpoint. The log segment doesn't need to get archived - it's

Re: [HACKERS] Reducing bgwriter wakeups

2012-02-19 Thread Jeff Janes
On Sun, Feb 19, 2012 at 2:18 PM, Robert Haas wrote: > > Also, in general, I think that it's not a good idea to let dirty data > sit in shared_buffers forever.  I'm unhappy about the change this > release cycle to skip checkpoints if we've written less than a full > WAL segment, and this seems like

Re: [HACKERS] Reducing bgwriter wakeups

2012-02-19 Thread Robert Haas
On Sun, Feb 19, 2012 at 4:11 PM, Simon Riggs wrote: > On Sun, Feb 19, 2012 at 8:15 PM, Robert Haas wrote: >> On Sun, Feb 19, 2012 at 1:53 PM, Simon Riggs wrote: >>> Recent changes for power reduction mean that we now issue a wakeup >>> call to the bgwriter every time we set a hint bit. >>> >>> H

Re: [HACKERS] Reducing bgwriter wakeups

2012-02-19 Thread Simon Riggs
On Sun, Feb 19, 2012 at 8:15 PM, Robert Haas wrote: > On Sun, Feb 19, 2012 at 1:53 PM, Simon Riggs 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

Re: [HACKERS] Reducing bgwriter wakeups

2012-02-19 Thread Robert Haas
On Sun, Feb 19, 2012 at 1:53 PM, Simon Riggs 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

[HACKERS] Reducing bgwriter wakeups

2012-02-19 Thread Simon Riggs
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 doi