Re: [PATCH RFC V4 0/5] kvm : Paravirt-spinlock support for KVM guests
From: Srivatsa Vaddagiri <hidden>
Date: 2012-01-16 14:20:23
Also in:
kvm, xen-devel
From: Srivatsa Vaddagiri <hidden>
Date: 2012-01-16 14:20:23
Also in:
kvm, xen-devel
* Alexander Graf [off-list ref] [2012-01-16 04:57:45]:
Speaking of which - have you benchmarked performance degradation of pv ticket locks on bare metal?
You mean, run kernel on bare metal with CONFIG_PARAVIRT_SPINLOCKS enabled and compare how it performs with CONFIG_PARAVIRT_SPINLOCKS disabled for some workload(s)? In some sense, the 1x overcommitcase results posted does measure the overhead of (pv-)spinlocks no? We don't see any overhead in that case for atleast kernbench ..
Result for Non PLE machine : ============================
[snip]
Kernbench:
BASE BASE+patch
%improvement
mean (sd) mean (sd)
Scenario A:
case 1x: 164.233 (16.5506) 163.584 (15.4598 0.39517[snip]
Result for PLE machine: ======================
[snip]
Kernbench:
BASE BASE+patch
%improvement
mean (sd) mean (sd)
Scenario A:
case 1x: 161.263 (56.518) 159.635 (40.5621) 1.00953- vatsa