Re: CVS commit: [uebayasi-xip] src/sys/miscfs/genfs

[Masao Uebayashi <uebayasi%tombi.co.jp@localhost>]

> what's the point of implementing it in the single VOP?
> ie. how is it better than having VOP_GETPAGES_XIP and pgo_get_xip?

Why not adding VOP_GETPAGES_XIP - because XIP is almost transparent to
filesystems.  The difference between XIP or not is only where to get pages,
which is beyond filesystem's task.

Why not adding pgo_get_xip - because I didn't think it's worth adding it.
XIP is transparent to other UVM pagers.  (And only used by vnode anyway.)

Why not done in pgo_get (uvn_get) - it's possible.  My 1st implementation
did the task in uvn_get().  I've changed it because what it does is close to
(generic) genfs_getpages().

> is it allowed to return both of "device pages" and normal pages mixed
> for a request?

That should work.  Once vm_page *[] are filled and passed back to UVM, they're
deal with one-by-one.

Masao

-- 
Masao Uebayashi / Tombi Inc. / Tel: +81-90-9141-4635