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authorHollis Blanchard <hollisb@us.ibm.com>2008-12-02 16:51:57 -0500
committerAvi Kivity <avi@redhat.com>2008-12-31 09:55:41 -0500
commit73e75b416ffcfa3a84952d8e389a0eca080f00e1 (patch)
tree6195be5b0fa56235550679f35ca990093dd081ca /arch/powerpc/kvm/Kconfig
parentc5fbdffbda79254047ec83b09c1a61a3655d052a (diff)
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 <ehrhardt@linux.vnet.ibm.com> Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/powerpc/kvm/Kconfig')
-rw-r--r--arch/powerpc/kvm/Kconfig11
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/Kconfig b/arch/powerpc/kvm/Kconfig
index e4ab1c7fd925..6dbdc4817d80 100644
--- a/arch/powerpc/kvm/Kconfig
+++ b/arch/powerpc/kvm/Kconfig
@@ -32,6 +32,17 @@ config KVM_440
32 32
33 If unsure, say N. 33 If unsure, say N.
34 34
35config KVM_EXIT_TIMING
36 bool "Detailed exit timing"
37 depends on KVM
38 ---help---
39 Calculate elapsed time for every exit/enter cycle. A per-vcpu
40 report is available in debugfs kvm/vm#_vcpu#_timing.
41 The overhead is relatively small, however it is not recommended for
42 production environments.
43
44 If unsure, say N.
45
35config KVM_TRACE 46config KVM_TRACE
36 bool "KVM trace support" 47 bool "KVM trace support"
37 depends on KVM && MARKERS && SYSFS 48 depends on KVM && MARKERS && SYSFS