On 09/25/2012 04:43 PM, Jiannan Ouyang wrote: > I've actually implemented this preempted_bitmap idea. Interesting, please share the code if you can. > However, I'm doing this to expose this information to the guest, so the > guest is able to know if the lock holder is preempted or not before > spining. Right now, I'm doing experiment to show that this idea works. > > I'm wondering what do you guys think of the relationship between the > pv_ticketlock approach and PLE handler approach. Are we going to adopt > PLE instead of the pv ticketlock, and why? Right now we're searching for the best solution. The tradeoffs are more or less: PLE: - works for unmodified / non-Linux guests - works for all types of spins (e.g. smp_call_function*()) - utilizes an existing hardware interface (PAUSE instruction) so likely more robust compared to a software interface PV: - has more information, so it can perform better Given these tradeoffs, if we can get PLE to work for moderate amounts of overcommit then I'll prefer it (even if it slightly underperforms PV). If we are unable to make it work well, then we'll have to add PV. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
