Ingo Molnar wrote: > * Ingo Molnar <[EMAIL PROTECTED]> wrote: > > >>> dyntick-enabled guest: >>> - reduce the load on the host when the guest is idling >>> (currently an idle guest consumes a few percent cpu) >>> >> yeah. KVM under -rt already works with dynticks enabled on both the >> host and the guest. (but it's more optimal to use a dedicated >> hypercall to set the next guest-interrupt) >> > > using the dynticks code from the -rt kernel makes the overhead of an > idle guest go down by a factor of 10-15: > > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND > 2556 mingo 15 0 598m 159m 157m R 1.5 8.0 0:26.20 qemu > >
As usual, great news. > ( for this to work on my system i have added a 'hyper' clocksource > hypercall API for KVM guests to use - this is needed instead of the > running-to-slowly TSC. ) > What's the problem with the TSC? The only issue I'm aware of is that the tsc might go backwards if the vcpu is migrated to another host cpu (easily fixed). A pv clocksource makes sense in any case. -- Do not meddle in the internals of kernels, for they are subtle and quick to panic. ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ kvm-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/kvm-devel
