Re: Random file I/O regressions in 2.6

Peter Zaitsev
2004-05-03T22:01:45Z

On Mon, 2004-05-03 at 14:50, Ram Pai wrote:

>
> Looking at it the other way, without readahead code, all requests
> satisfied through 4k i/os. Readahead helps in generating larger size
> i/os.

Huh, This is kind of really strange.

If you speak about database world, Random IO is quite frequent and
database page sizes are normally larger than OS page size.

Furthermore even if it is split to 4K block sizes, why are they not
submitted in parallel, being merged on lower level.

Anyway we seems to all agree this is not very good behavior and it
should be fixed :)

--
Peter Zaitsev, Senior Support Engineer
MySQL AB, www.mysql.com