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Re: [Xen-devel] Re: [Xen-users] cache for partition based VBD?

On Tue, 29 Nov 2005 17:44:34 -0600
Tim Freeman <tfreeman@xxxxxxxxxxx> wrote:

> On Tue, 29 Nov 2005 18:56:32 +0100
> "Petersson, Mats" <mats.petersson@xxxxxxx> wrote:
> [...]
> > > I think that the Linux architecture puts the buffer cache in 
> > > front of all block device access, not at the VFS layer.  So 
> > > does that answer the question?  The dom0 disk backend driver 
> > > sits "above" the buffer cache?  (sorry for my crude
> > > understanding)
> > 
> > I would say that this is correct - the Dom0 disk driver would have a
> > cache in itself, and the DomU would also have a caching layer. But I'm
> > not SURE about this at all. 
> > 
> > If someone can make further comments, it would be great. 
> I found this post that directly addresses the point:
> http://lists.xensource.com/archives/html/xen-devel/2005-05/msg01167.html
> (now the experimental data makes less sense to me)

Regarding that thread (and one of my own questions), I did find this patch for
clearing the page cache entirely (not just flushing pending writes)...



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