> >> since several months >> ago when I tested the in- kernel- apic the idle time was much worse. >After >> talking today with Avi, he said his vmentry- exit latency drastically >> improved performance and even the qemu's apic can reach these figures. > >Yeah. At first I was psyched when I saw my code running at 0-1%, but then >I ran trunk and saw its not all that different :( The good news is that >windows is performing pretty well now, regardless of my patch or not. >Thats good for KVM all around. > >> I'm sure that with load, you implementation will achieve performance >> advantage. > >In theory, we should be able to take advantage of all the light-exit gains >we have made recently since that is the primary difference for windows+ACPI >now. This means the APIC change will have an increasing impact as we >improve the VMEXIT times (both in HW and SW). So even if it doesn't make a >huge diff today, it will always be contributing more and more as we push >the ball forward in other areas. > >But I am not disappointed. My primary motivation is functionality, not >performance. ;) I need to be able to inject interrupts to a guest from the >kernel for the work I am doing. If I also improve performance, great! >
Your timing is good for us too since we have our pv network driver that now works with qemu's interrupts. This means that we use a signal in order to inject rx packets to the guest. In-kernel apic should improve that, I'll soon measure the diff although using NAPI might dissolve the performance gain. It's good stuff the apic will be in the kernel, once it's there we need to consider other components too. ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ kvm-devel mailing list kvm-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/kvm-devel
