Re: [PATCH] O_STREAMING - flag for optimal streaming I/O

From: Mark Mielke (mark@mark.mielke.cc)
Date: Wed Oct 09 2002 - 22:07:36 EST

On Thu, Oct 10, 2002 at 12:20:02AM +0100, Jamie Lokier wrote:
> Mark Mielke wrote:
> > 2) Pages should not be candidates for dropping if the pages belong
> > to the first few pages of a file. (First = 2? 4? 8?) The theory
> > being, that somebody could begin reading the file again from the
> > beginning.
> This breaks the benefit of using O_STREAMING to read a lot of small
> files once, as you might do when grepping the kernel tree for example.

It doesn't break it. It reduces it to current speeds.

I might be wrong, but it seems to me that O_STREAMING isn't the answer
to everything. The primary benefactors of O_STREAMING would be
applications that read very large files that do not fit into RAM, from
start to finish.

If you want to improve grepping the kernel tree, the answer lies in
improving the standard scheme, not overloading the specialized
O_STREAMING scheme.

mark 

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