Bruce Momjian <pgman@candle.pha.pa.us> writes:
> I am confused. If we change the percentage to be X% of the entire
> buffer cache, and we set it to 1%, and we exit when either the dirty
> pages or % are reached, don't we end up just scanning the first 1% of
> the cache over and over again?
Exactly. But 1% would be uselessly small with this definition. Offhand
I'd think something like 50% might be a starting point; maybe even more.
What that says is that a page isn't a candidate to be written out by the
bgwriter until it's fallen halfway down the LRU list.
regards, tom lane