Re: readahead benchmark

Andrew Morton
2006-06-05T01:02:12Z

On Mon, 5 Jun 2006 08:28:07 +0800
Fengguang Wu <fengguang.wu@gmail.com> wrote:

> On Sun, Jun 04, 2006 at 01:50:11PM -0700, Andrew Morton wrote:
> > readahead-kconfig-options.patch
> [...]
> > It's early days yet - needs heaps more performance testing. The results
> > from "Linux Portal" <linportal@gmail.com> were discouraging.
>
> I found this mail from the lkml archive, did you happen to have more
> results?
>

Sorry, I had the wrong tester. Voluspa <lista1@comhem.se>: "Conclusion: On
_this_ machine, with _these_ operations, Adaptive Readahead in its current
incarnation and default settings is a _loss_."

>
> There is an interesting (although simple) benchmark of Wu's adaptive
> readahead patchset (v12) together with graphs here:
>
> http://linux.inet.hr/adaptive_readahead_benchmark.html
>
> In that simple test it definitely looks promising (3x speedup).

That's postgreql again.

We know there's a problem at present with postgresql. Has anyone tried to
fix it, without going and rewriting everything?