Re: [RESEND] [PATCH] readahead:add blk_run_backing_dev

Kurt Garloff
2009-07-15T20:51:47Z

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Hi,

On Wed, Jul 08, 2009 at 04:40:08PM +0400, Vladislav Bolkhovitin wrote:
> I've also long ago noticed that reading data from block devices is slower
> than from files from mounted on those block devices file systems. Can
> anybody explain it?

Brainstorming:
- block size (reads on the block dev might be done with smaller size)
- readahead (do we use the same RA algo for block devs)
- page cache might be better optimized than buffer cache?

Just guesses from someone that has not looked into that area of the
kernel for a while, so take it with a grain of salt.

Cheers,
--
Kurt Garloff, VP OPS Partner Engineering -- Novell Inc.

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