From 73e75b416ffcfa3a84952d8e389a0eca080f00e1 Mon Sep 17 00:00:00 2001 From: Hollis Blanchard Date: Tue, 2 Dec 2008 15:51:57 -0600 Subject: KVM: ppc: Implement in-kernel exit timing statistics Existing KVM statistics are either just counters (kvm_stat) reported for KVM generally or trace based aproaches like kvm_trace. For KVM on powerpc we had the need to track the timings of the different exit types. While this could be achieved parsing data created with a kvm_trace extension this adds too much overhead (at least on embedded PowerPC) slowing down the workloads we wanted to measure. Therefore this patch adds a in-kernel exit timing statistic to the powerpc kvm code. These statistic is available per vm&vcpu under the kvm debugfs directory. As this statistic is low, but still some overhead it can be enabled via a .config entry and should be off by default. Since this patch touched all powerpc kvm_stat code anyway this code is now merged and simplified together with the exit timing statistic code (still working with exit timing disabled in .config). Signed-off-by: Christian Ehrhardt Signed-off-by: Hollis Blanchard Signed-off-by: Avi Kivity --- arch/powerpc/kvm/Kconfig | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'arch/powerpc/kvm/Kconfig') diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig index e4ab1c7..6dbdc48 100644 --- a/arch/powerpc/kvm/Kconfig +++ b/arch/powerpc/kvm/Kconfig @@ -32,6 +32,17 @@ config KVM_440 If unsure, say N. +config KVM_EXIT_TIMING + bool "Detailed exit timing" + depends on KVM + ---help--- + Calculate elapsed time for every exit/enter cycle. A per-vcpu + report is available in debugfs kvm/vm#_vcpu#_timing. + The overhead is relatively small, however it is not recommended for + production environments. + + If unsure, say N. + config KVM_TRACE bool "KVM trace support" depends on KVM && MARKERS && SYSFS -- cgit v1.1