Re: [Kiobuf-io-devel] RFC: Kernel mechanism: Compound event wait /notify + callback chains

Christoph Hellwig
2001-02-01T15:10:35Z

On Thu, Feb 01, 2001 at 08:14:58PM +0530, bsuparna@in.ibm.com wrote:
>
> >Hi,
> >
> >On Thu, Feb 01, 2001 at 10:25:22AM +0530, bsuparna@in.ibm.com wrote:
> >>
> >> >We _do_ need the ability to stack completion events, but as far as the
> >> >kiobuf work goes, my current thoughts are to do that by stacking
> >> >lightweight "clone" kiobufs.
> >>
> >> Would that work with stackable filesystems ?
> >
> >Only if the filesystems were using VFS interfaces which used kiobufs.
> >Right now, the only filesystem using kiobufs is XFS, and it only
> >passes them down to the block device layer, not to other filesystems.
>
> That would require the vfs interfaces themselves (address space
> readpage/writepage ops) to take kiobufs as arguments, instead of struct
> page * . That's not the case right now, is it ?

No, and with the current kiobufs it would not make sense, because they
are to heavy-weight. With page,length,offsett iobufs this makes sense
and is IMHO the way to go.

Christoph

--
Of course it doesn't work. We've performed a software upgrade.