Subject: Re: yamt-readahead branch
To: None <jonathan@dsg.stanford.edu>
From: YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
List: tech-kern
Date: 11/16/2005 12:53:22
> > - I see you have some XXX comments about tuning the amount of data to
> > read ahead based on physical memory, which is true, but we should also
> > tune based on the I/O throughput of the underlying device. we want to
> > be able to keep any device 100% busy, ideally without the user needing
> > to configure this manually. but we'll need some way to allow manual
> > per-device tuning as well.
>
> No, in point of fact, for NFS, I/O throughput rate is not enough: one
> really need to issue sufficient readahed to fill the bandwidth-delay product.
i don't think it needs a special treatment.
keeping devices busy and keeping network busy is the same thing
in the POV of read-ahead code.
YAMAMOTO Takashi