path: root/docs/testing/user/userguide
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authorkalyanreddy <reddyx.gundarapu@intel.com>2017-05-25 15:01:40 +0530
committerKalyan reddy Gundarapu <reddyx.gundarapu@intel.com>2017-05-31 08:33:17 +0000
commita6a5c653357cf0fd82c489501b6bdbacb2aaf65b (patch)
treee4b423e661fb1f07769025ede12b95f69030f5d1 /docs/testing/user/userguide
parente71e24ec001cfc06e27ce12c081ba749948b4599 (diff)
Qemu: Mechanism to pass extra qemu cpu features and pin vCPU threads
JIRA: VSPERF-510 This patch is used to implement the mechanism to pass extra qemu cpu options required to achieve better results/performance. Also used to implement a mechanism to pin the vCPU threads to another pCPU core which helps in reducing the noise from housekeeping thread and packet loss. Change-Id: Ic40fd47d7c4f5556f7e240c6ca671a0535d06ece Signed-off-by: Gundarapu Kalyan Reddy <reddyx.gundarapu@intel.com>
Diffstat (limited to 'docs/testing/user/userguide')
1 files changed, 40 insertions, 0 deletions
diff --git a/docs/testing/user/userguide/testusage.rst b/docs/testing/user/userguide/testusage.rst
index 043ef92..f849076 100644
--- a/docs/testing/user/userguide/testusage.rst
+++ b/docs/testing/user/userguide/testusage.rst
@@ -570,6 +570,46 @@ Note: vfio_no_iommu requires kernels equal to or greater than 4.5 and dpdk
Please refer to the dpdk documents at http://dpdk.org/doc/guides for more
information on these drivers.
+Guest Core and Thread Binding
+VSPERF provides options to achieve better performance by guest core binding and
+guest vCPU thread binding as well. Core binding is to bind all the qemu threads.
+Thread binding is to bind the house keeping threads to some CPU and vCPU thread to
+some other CPU, this helps to reduce the noise from qemu house keeping threads.
+.. code-block:: python
+**NOTE** By default the GUEST_THREAD_BINDING will be none, which means same as
+the GUEST_CORE_BINDING, i.e. the vcpu threads are sharing the physical CPUs with
+the house keeping threads. Better performance using vCPU thread binding can be
+achieved by enabling affinity in the custom configuration file.
+For example, if an environment requires 32,33 to be core binded and 29,30&31 for
+guest thread binding to achieve better performance.
+.. code-block:: python
+ GUEST_CORE_BINDING = [('32','33')]
+ GUEST_THREAD_BINDING = [('29', '30', '31')]
+Qemu CPU features
+QEMU default to a compatible subset of performance enhancing cpu features.
+To pass all available host processor features to the guest.
+.. code-block:: python
+ GUEST_CPU_OPTIONS = ['host,migratable=off']
+**NOTE** To enhance the performance, cpu features tsc deadline timer for guest,
+the guest PMU, the invariant TSC can be provided in the custom configuration file.
Multi-Queue Configuration