Re: Proposed LogWriter Scheme, WAS: Potential Large

Hannu Krosing <hannu@tm.ee>

From: Hannu Krosing <hannu@tm.ee>
To: Neil Conway <neilc@samurai.com>
Cc: Greg Copeland <greg@CopelandConsulting.Net>, Antti Haapala <antti.haapala@iki.fi>, Curtis Faith <curtis@galtair.com>, Bruce Momjian <pgman@candle.pha.pa.us>, Pgsql-Hackers <pgsql-hackers@postgresql.org>
Date: 2002-10-07T19:32:42Z
Lists: pgsql-hackers
On Mon, 2002-10-07 at 21:35, Neil Conway wrote:
> Greg Copeland <greg@CopelandConsulting.Net> writes:
> > Ya, I have read this before.  The problem here is that I'm not aware of
> > which AIO implementation on Linux is the forerunner nor do I have any
> > idea how it's implementation or performance details defer from that of
> > other implementations on other platforms.
> 
> The implementation of AIO in 2.5 is the one by Ben LaHaise (not
> SGI). Not sure what the performance is like -- although it's been
> merged into 2.5 already, so someone can do some benchmarking. Can
> anyone suggest a good test?

What would be really interesting is to aio_write small chunks to the
same 8k page by multiple threads/processes and then wait for the page
getting written to disk.

Then check how many backends get their wait back at the same write. 

The docs for POSIX aio_xxx are at:

http://www.opengroup.org/onlinepubs/007904975/functions/aio_write.html

----------------
Hannu