Re: PATCH: killing read_ahead[]

From: Rik van Riel (riel@conectiva.com.br)
Date: Wed Oct 25 2000 - 09:28:06 EST


On Tue, 24 Oct 2000, Linus Torvalds wrote:
> On Tue, 24 Oct 2000, Jeff Garzik wrote:
> >
> > I agree with you and Rik that this array needs to go away... but
> > ripping out the feature is not the answer, IMHO.
>
> Actually, the _real_ answer is to make fs/block_dev.c use the
> page cache instead - and generic_file_read() does read-ahead
> that actually improves performance, unlike the silly contortions
> that the direct block-dev read-ahead tries to do.

OTOH, block-dev readahead makes sense for filesystems where
the packing locality is close to the access pattern BUT NOT
close to anything the page cache would recognise as being
close.

Then again ... that's a filesystem issue, not a block device
issue. ;)

regards,

Rik

--
"What you're running that piece of shit Gnome?!?!"
       -- Miguel de Icaza, UKUUG 2000

http://www.conectiva.com/ http://www.surriel.com/

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