Re: Dirty Buffer Writing [was Proposed LogWriter Scheme]

Curtis Faith <curtis@galtair.com>

From: "Curtis Faith" <curtis@galtair.com>
To: "Bruce Momjian" <pgman@candle.pha.pa.us>
Cc: "Greg Copeland" <greg@copelandconsulting.net>, "Pgsql-Hackers" <pgsql-hackers@postgresql.org>, "Tom Lane" <tgl@sss.pgh.pa.us>
Date: 2002-10-07T20:43:20Z
Lists: pgsql-hackers
> This is the trickle syncer.  It prevents bursts of disk activity every
> 30 seconds.  It is for non-fsync writes, of course, and I assume if the
> kernel buffers get low, it starts to flush faster.

AFAICT, the syncer only speeds up when virtual memory paging fills the
buffers past
a threshold and even in that event it only speeds it up by a factor of two.

I can't find any provision for speeding up flushing of the dirty buffers
when they fill for normal file system writes, so I don't think that
happens.

- Curtis