Re: [parisc-linux] rmap: parisc __flush_dcache_page

[James Bottomley <James.Bottomley@steeleye.com>]

On Thu, 2004-04-08 at 12:10, Andrea Arcangeli wrote:
> I said above per-arch abstraction, a per-arch abstraction isn't an irq
> safe spinlock, we cannot add an irq safe spinlock there, it'd be too bad
> for all the common archs that don't need to walk those lists (actually
> trees in my -aa tree) from irq context.

I think we agree on the abstraction thing.  I was more wondering what
you thought was so costly about an irq safe spinlock as opposed to an
ordinary one?  Is there something adding to this cost I don't know
about?  i.e. should we be thinking about something like RCU or phased
tree approach to walking the mapping lists?

James