On May 24, 2005, at 9:37 AM, Manuel Bouyer wrote:

> Yes (I guess otherwise, the free routine woudln't be called).
> The problem I have is if an additionnal mapping has existed and has  
> been
> removed, the removal may still be in Xen's pmap update queue (that is,
> it may still be effectively mapped). Flushing the pmap update queue  
> from the
> mbuf free routine cause problems (because it can be called from  
> interrupt
> context), and I could just skip this if I was sure that no additionnal
> mapping ever existed for this buffer.

Perhaps you could put in a DEBUG-only assertion that the queue is  
empty.  There should not be any other mappings for buffers that are  
being ext_free'd.

-- thorpej