Re: [PATCH 2 of 4] xenpaging: use wait queues

[Olaf Hering <olaf@aepfle.de>]

On Fri, Dec 02, Andres Lagar-Cavilla wrote:

> A pager could nominate gfn's in batches, write them out in batches, evict
> them in batches. It's a bit of a longshot, but exemplifies the kinds of
> problems we need to think about when tinkering with the paging ABI.

I want to do something like that, using a separate ring instead of
individual domctls. However, its more an optimization than a bugfix so
its not a top priority for me. I see you already submitted changes to
simplify event channel handling.

> On that topic. Is there a reason why a page cannot be proactively paged in
> without attempting to map it first? I.e. move from p2m_ram_paging_out
> straight into p2m_ram_paging_in with paging_prep/_load? It would eliminate
> xenpaging's use of a page-in thread...

Maybe there are different ways to do that. The way ring buffers are
implemented now its not possible to send one-way events with the ring.

Olaf