From: | Stephen Frost <sfrost(at)snowman(dot)net> |
---|---|
To: | Merlin Moncure <mmoncure(at)gmail(dot)com> |
Cc: | Andres Freund <andres(at)2ndquadrant(dot)com>, Heikki Linnakangas <hlinnakangas(at)vmware(dot)com>, Greg Stark <stark(at)mit(dot)edu>, Robert Haas <robertmhaas(at)gmail(dot)com>, Peter Geoghegan <pg(at)heroku(dot)com>, Pg Hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: Clock sweep not caching enough B-Tree leaf pages? |
Date: | 2014-04-17 19:00:07 |
Message-ID: | 20140417190007.GO2556@tamriel.snowman.net |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
* Merlin Moncure (mmoncure(at)gmail(dot)com) wrote:
> I doubt that's necessary though -- if the postgres caching algorithm
> improves such that there is a better tendency for hot pages to stay in
> s_b, Eventually the O/S will deschedule the page for something else
> that needs it. In other words, otherwise preventable double
> buffering is really a measurement of bad eviction policy because it
> manifests in volatility of frequency accessed pages.
I wonder if it would help to actually tell the OS to read in buffers
that we're *evicting*... On the general notion that if the OS already
has them buffered then it's almost a no-op, and if it doesn't and it's
actually a 'hot' buffer that we're gonna need again shortly, the OS will
have it.
In other words, try to make the OS more like a secondary cache to ours
by encouraging it to cache things we're evicting.
Thanks,
Stephen
From | Date | Subject | |
---|---|---|---|
Next Message | Merlin Moncure | 2014-04-17 19:05:21 | Re: Clock sweep not caching enough B-Tree leaf pages? |
Previous Message | Peter Geoghegan | 2014-04-17 18:55:51 | Re: Clock sweep not caching enough B-Tree leaf pages? |