Re: 2.2.6_andrea2.bz2

[Andi Kleen <ak@muc.de>]

On Mon, Apr 26, 1999 at 10:05:56AM +0200, Eric W. Biederman wrote:
> >>>>> "AA" == Andrea Arcangeli <andrea@e-mind.com> writes:
> 
> >>> o	update_shared_mappings (will greatly improve performances while
> >>> writing from many task to the same shared memory).
> >> 
> >> do you have performance numbers on this?
> 
> AA> The performance optimization can be huge.
> 
> AA> The reason this my code is not in the kernel is not because it's buggy but
> AA> simple because there are plans for 2.3.x (no-way for 2.2.x) to allow the
> AA> file cache to be dirty (to cache also writes and not only read in the page
> AA> cache).
> 
> Andrea.  The plan (at least my plan) is not to have 2 layers of buffers.
> Instead it is to do all of the caching (except for perhaps superblocks, and their
> kin in the page cache).  brw_page will be used for both reads and writes, with
> anonymouse buffer heads (at least for a start).

Stupid question: do you plan to cache fs metadata in the page cache too? 
If yes, it is rather wasteful to use a 4K page for the usually block sized
directories and other fs data like indirect blocks. How do you plan to 
address this problem?


-Andi
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