Re: pagebuf page cleaner and page aging

[Christoph Hellwig <hch@xxxxxxxxxx>]

On Fri, Jan 19, 2001 at 12:38:27PM -0200, Marcelo Tosatti wrote:
> Obviously the VM does not have knowledge about the filesystem low-level
> information, which is also needed to get write clustering right.

IMHO we should try to give the VM knowlede how to cluster without
having to go into the low-level code at all.
The idea I had for such information is the notation of a virtual extent.
A virtual extend would simply be a list-head in the struct page that links
a pages together that are worth clustering because they are either real
extents (because the fs supports it) or just continguos aligned on disk
for block-based filesystems (yeah, we have to do magic on readtime to
get this information, best by a readpage op).

The disadvantage of this appropeach is that it bloats struct page even more...

        Christoph

-- 
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