On Wed, 2008-12-03 at 13:32 +0200, Avi Kivity wrote: > Hollis Blanchard wrote: > > Hi Avi, here's the latest batch of PowerPC kernel patches. > > > > The first set dramatically improve performance. Most importantly, we add > > support for large host pages with KVM (i.e. PAGE_SHIFT > 12). (Large *guest* > > pages have already been supported since day 1, since the guest kernel uses > > them for the linear map.) Followup patches further improve performance by > > changing how we manage the shadow TLB. > > > > The last two add some accounting code to easily discover performance > > bottlenecks. This is especially important since the 440 core lacks performance > > monitoring hardware. > > > > These patches, in conjunction with 64KB pages on guest and host, get us to 96% > > of native performance for compute-bound workloads, which I'm pretty happy > > with. See http://kvm.qumranet.com/kvmwiki/PowerPC_Exittimings for more > > details (those statistics were gathered using the accounting patches). > > > > These have been tested pretty thoroughly for several weeks. Please apply for > > 2.6.29. Thanks! > > > > Applied all, thanks. Thanks. > I'm not thrilled about the private exit timing statistics gathering, > hopefully it can be morphed into the more general framework. Is there anything in particular you have in mind? I think it could be generally useful, but since x86 has hardware support for performance monitoring, oprofile will already give you more accurate information. Of course, I don't think you could extract standard deviation from an oprofile report, and that has been very useful for us because it can tell us e.g. 99% of instruction emulation is handled in the minimum amount of time, but 1% takes hundreds of ms. I'll let Christian comment when he gets back from vacation on Monday. -- Hollis Blanchard IBM Linux Technology Center -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
