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Date: Wed, 09 Oct 2002 01:43:35 -0700
From: Andrew Morton <akpm@digeo.com>
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To: Giuliano Pochini <pochini@shiny.it>
CC: Robert Love <rml@tech9.net>, riel@conectiva.com.br,
       linux-kernel@vger.kernel.org, Chris Wedgwood <cw@f00f.org>
Subject: Re: [PATCH] O_STREAMING - flag for optimal streaming I/O
References: <1034104637.29468.1483.camel@phantasy> <XFMail.20021009103325.pochini@shiny.it>
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Giuliano Pochini wrote:
> 
> > The point of O_STREAMING is one change: drop pages in the pagecache
> > behind our current position, that are free-able, because we know we will
> > never want them.
> 
> Does it drop pages unconditionally ?

Yup.

>  What happens if I do a
> streaming_cat largedatabase > /dev/null while other processes
> are working on it ?

You'll make your database run really slowly.

> It's not a good thing to remove the whole
> cached data other apps are working on.
> 

Don't do that then ;)

Seriously, there are tons of ways of creating local performance
DoS'es of this form.  fsync is an excellent tool for that.
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