Messages in this thread | | | Date | Wed, 04 Jan 2012 19:13:15 +0200 | From | Avi Kivity <> | Subject | Re: [RFC PATCH 0/4] Gang scheduling in CFS |
| |
On 01/04/2012 04:56 PM, Srivatsa Vaddagiri wrote: > * Avi Kivity <avi@redhat.com> [2012-01-04 16:41:58]: > > > > Here are some observation related to Baseline-only(8vm case) > > > > > > | ple_gap=128 | ple_gap=64 | ple_gap=256 | ple_window=2048 > > > --------------+-------------+------------+-------------+---------------- > > > EbzyRecords/s | 2247.50 | 2132.75 | 2086.25 | 1835.62 > > > PauseExits | 7928154.00 | 6696342.00 | 7365999.00 | 50319582.00 > > > > > > With ple_window = 2048, PauseExits is more than 6times the default case > > > > So it looks like the default is optimal, at least wrt the cases you > > tested and your test workload. > > The default case still lags considerably behind the results we are seeing with > gang scheduling. One more interesting data point would be to see how > many PLE exits we are seeing when the vcpu is spinning in > flush_tlb_others_ipi(). Is there any easy way to determine that? >
You could get an exit trace (trace-cmd -e kvm:kvm_exit) and filter on PLE exits; the trace contains the guest %rip, so you could match it against flush_tlb_others_ipi().
-- error compiling committee.c: too many arguments to function
| |