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

Re: [Xen-devel] Why is 'emulate' as good as writable PT's?

Keir Fraser wrote:

On 6 Jun 2006, at 21:28, Andrew Theurer wrote:

Yes, we definitely have a problem here. Tons of flushes with modified=1, and lots with <=10. The three benchmarks all seem to hit the same areas. Here is the output from running SDET, with snippets from System.map mixed in:

Is this PAE? SMP guest?

Do you know much about the SDET benchmark? For example, do you know how big the mprotect() calls it makes are likely to be? If vma's are small and fairly sparse then the writable pagetable batching won't be a win.
1-way SMP kernel, PAE. not sure about the mprotect() calls. SDET basically calls a lot of utilities like ps, gcc, ispell, etc. Is it feasible to "xen-ify" unmap_vmas() and copy_page_range(), such that we use explicit hypercalls instead of faulting on the writes?


Xen-devel mailing list



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