f125a8b892
This change addresses a long-standing issue in rST documentation imported from XML.
That import process added backslash escapes in front of various characters. The three
most common being '(', ')', and '_'.
These instances are removed.
Signed-off-by: Ron Stone <ronald.stone@windriver.com>
Change-Id: Id43a9337ffcd505ccbdf072d7b29afdb5d2c997e
82 lines
2.8 KiB
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82 lines
2.8 KiB
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.. jow1454003783557
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.. _resource-planning:
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==================
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Resource Placement
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==================
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.. only:: starlingx
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For |VMs| requiring maximum determinism and throughput, the |VM| must be
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placed in the same NUMA node as all of its resources, including |VM|
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memory, |NICs|, and any other resource such as |SRIOV| or |PCI|-Passthrough
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devices.
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VNF 1 and VNF 2 in the example figure are examples of |VMs| deployed for
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maximum throughput with |SRIOV|.
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.. only:: starlingx
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A |VM| such as VNF 6 in NUMA-REF will not have the same performance as VNF
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1 and VNF 2. There are multiple ways to maximize performance for VNF 6 in
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this case:
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.. From NUMA-REF
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.. xbooklink :ref:`VM scheduling and placement - NUMA
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architecture <vm-scheduling-and-placement-numa-architecture>`
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.. only:: partner
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.. include:: /_includes/resource-planning.rest
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:start-after: avs-text-1-begin
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:end-before: avs-text-2-end
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.. only:: partner
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.. include:: /_includes/resource-planning.rest
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:start-after: avs-text-2-begin
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:end-before: avs-text-2-end
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.. _resource-planning-ul-tcb-ssz-55:
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.. only:: partner
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.. include:: /_includes/resource-planning.rest
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:start-after: avs-text-1-end
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If accessing |PCIe| devices directly from a |VM| using |PCI|-Passthrough or
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|SRIOV|, maximum performance can only be achieved by pinning the |VM| cores
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to the same NUMA node as the |PCIe| device. For example, VNF1 and VNF2
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will have optimum SR-IOV performance if deployed on NUMA node 0 and VNF6
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will have maximum |PCI|-Passthrough performance if deployed in NUMA node 1.
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Options for controlling access to |PCIe| devices are:
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.. _resource-planning-ul-ogh-xsz-55:
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- Use pci_numa_affinity flavor extra specs to force VNF6 to be scheduled on
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NUMA nodes where the |PCI| device is running. This is the recommended option
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because it does not require prior knowledge of which socket a |PCI| device
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resides on. The affinity may be **strict** or **prefer**:
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- **Strict** affinity guarantees scheduling on the same NUMA node as a
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|PCIe| Device or the VM will not be scheduled.
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- **Prefer** affinity uses best effort so it will only schedule the VM on
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a NUMA node if no NUMA nodes with that |PCIe| device are available. Note
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that prefer mode does not provide the same performance or determinism
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guarantees as strict, but may be good enough for some applications.
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- Pin the VM to the NUMA node 0 with the |PCI| device using flavor extra
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specs or image properties. This will force the scheduler to schedule the VM
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on NUMA node 0. However, this requires knowledge of which cores the
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applicable |PCIe| devices run on and does not work well unless all nodes
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have that type of |PCIe| node attached to the same socket.
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