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Date: Wed, 9 Oct 2002 16:14:35 +0200 (CEST)
From: Marco Colombo <marco@esi.it>
To: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] O_STREAMING - flag for optimal streaming I/O
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On Tue, 8 Oct 2002, Andrew Morton wrote:

> I'd say that if you were designing a new application which
> streams large amount of data then yes, you would design it
> to use O_DIRECT.  You would instantiate a separate IO worker
> thread and a message passing mechanism so that thread would
> pump your data for you, and would peform your readahead, etc.
> 
> If your filesystem supports O_DIRECT, of course.  Not all do.
> 
> The strength of O_STREAMING is that you can take an existing,
> working, megahuge application and make it play better with the
> VM by changing a single line of code.  No big redesign needed.

Such as perl:

sysopen(MYKERNEL, "/boot/vmlinuz", 04000000);

O_DIRECT support is another beast, IMHO.

.TM.

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