[Ocfs2-devel] [PATCH V2 2/7] Cleancache (was Transcendent Memory): core files

[Jeremy Fitzhardinge]

On 06/02/2010 05:06 PM, Dan Magenheimer wrote:
> It is intended that there be different flavours but only
> one can be used in any running kernel.  A driver file/module
> claims the cleancache_ops pointer (and should check to ensure
> it is not already claimed).  And if nobody claims cleancache_ops,
> the hooks should be as non-intrusive as possible.
>
> Also note that the operations occur on the order of the number
> of I/O's, so definitely a lot, but "zillion" may be a bit high. :-)
>
> If you think this is a showstoppper, it could be changed
> to be bound only at compile-time, but then (I think) the claimer
> could never be a dynamically-loadable module.
>   

Andrew is suggesting that rather than making cleancache_ops a pointer to
a structure, just make it a structure, so that calling a function is a
matter of cleancache_ops.func rather than cleancache_ops->func, thereby
avoiding a pointer dereference.

    J