[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] where is writable page table implemented?



At 11:37 -0400 on 01 Apr (1207049874), weiming wrote:
> Do you know under which situation we use writable page table instead of
> calling update_va_mapping?

Not in any detail.

> And do you know the purpose of the counter defined in
> page_info.u.in_use.type_info?
> I understand that xen needs to keep track of the type of each page
> (L1_page_table_page, L2_page_table_page, pinned, unpinned, validated, etc),
> but why do we need to use the lower 26 bits of "type_info" as a counter? (in
> "get_page_type()", the counter is increased. )  Similarly,  get_page() /
> put_page() also increases/decreases the page.count_info. Could you please
> give me some hint about the usage of such counters?

You should read the comments at the top of xen/arch/x86/mm.c.

Tim.

-- 
Tim Deegan <Tim.Deegan@xxxxxxxxxx>
Principal Software Engineer, Citrix Systems (R&D) Ltd.
[Company #02300071, SL9 0DZ, UK.]

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.