[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] vnif socket buffer mistaken for pagetable page causes major performance problem
Gianluca Guida wrote: Herbert van den Bergh wrote:Can you be a little more specific about what is the performance loss,Network throughput was reduced to 10% of normal.in what workload,A network send throughput test using netperf.This is with a Linux guest (HVM of course), right? Right. The access pattern to the memory page that was recognized as a pagetable access was a regular memcpy doing 4 byte aligned writes into a newly allocated page. I'm not that familiar with the shadow pagetable code, so I don't know how "wrong" this is, just that it caused a false positive on this type of memory access.and what heuristic you found to be wrong in this case?Most probably the guest OS is recycling a page that used to be a pagetable and that is still shadowed.Thanks, Gianluca _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |