At 17:37 +0000 on 06 Nov (1446831437), David Vrabel wrote: > Holding the p2m lock while calling ept_sync_domain() is very expensive > since it does a on_selected_cpus() call. IPIs on many socket machines > can be very slows and on_selected_cpus() is serialized. > > Defer the invalidate until the p2m lock is released. Since the processor > may cache partial translations, we also need to make sure any page table > pages to be freed are not freed until the invalidate is complete. Such > pages are temporarily stored an per-PCPU list.
That seems like it could get messy if a PCPU might have multiple p2ms locked at once (e.g. nested HAP, altp2m). I think a per-p2m list would be more obviously correct, and not too expensive. Cheers, Tim. _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
