Re: [PATCH 1/8] block: limit default readahead size for small devices

[Christoph Hellwig]

On Mon, Nov 21, 2011 at 05:18:20PM +0800, Wu Fengguang wrote:
> This looks reasonable: smaller device tend to be slower (USB sticks as
> well as micro/mobile/old hard disks).
> 
> Given that the non-rotational attribute is not always reported, we can
> take disk size as a max readahead size hint. This patch uses a formula
> that generates the following concrete limits:

Given that you mentioned the rotational flag and device size in this
mail, as well as benchmarking with an intel SSD  -  did you measure
how useful large read ahead sizes still are with highend Flash device
that have extremly high read IOP rates?

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