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From: Daniel Phillips <phillips@bonn-fries.net>
To: Anton Altaparmakov <aia21@cam.ac.uk>
Subject: Re: [RFC] Optimization for use-once pages
Date: Wed, 25 Jul 2001 03:30:34 +0200
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On Wednesday 25 July 2001 02:43, Anton Altaparmakov wrote:
> At 01:04 25/07/2001, Daniel Phillips wrote:
> >At that size you'd run a real risk of missing the tell-tale multiple
> >references that mark a page as frequently used.  Think about
> > metadata here (right now, that usually just means directory pages,
> > but later... who knows).
>
> This is not actually implemented yet, but NTFS TNG will use the page
> cache to hold both the LCN (physical clusters) and MFT (on disk
> inodes) allocation bitmaps in addition to file and directory pages.
> (Admittedly the LCN case folds into the file pages in page cache one
> as the LCN bitmap is just stored inside the usual data of a file
> called $Bitmap, but the MFT case is more complex as it is in an
> additional attribute inside the file $MFT so the normal file
> read/write functions definitely cannot be used. The usual data here
> is the actual on disk inodes...)
>
> Just FYI.

Yes, not a surprise.  Plus, I was working on an experimental patch to 
put Ext2 index blocks into the page cache just before I got off on this 
use-once tangent.  Time to go back to that...

--
Daniel
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