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DPDK mempools rely on rte_lcore_id() to implement a thread-local cache.
Our non pmd threads had rte_lcore_id() == 0. This allowed concurrent access to
the "thread-local" cache, causing crashes.
This commit resolves the issue with the following changes:
- Every non pmd thread has the same lcore_id (0, for management reasons), which
is not shared with any pmd thread (lcore_id for pmd threads now start from 1)
- DPDK mbufs must be allocated/freed in pmd threads. When there is the need to
use mempools in non pmd threads, like in dpdk_do_tx_copy(), a mutex must be
held.
- The previous change does not allow us anymore to pass DPDK mbufs to handler
threads: therefore this commit partially revert 143859ec63. Now packets
are copied for upcall processing. We can remove the extra memcpy by
processing upcalls in the pmd thread itself.
With the introduction of the extra locking, the packet throughput will be lower
in the following cases:
- When using internal (tap) devices with DPDK devices on the same datapath.
Anyway, to support internal devices efficiently, we needed DPDK KNI devices,
which will be proper pmd devices and will not need this locking.
- When packets are processed in the slow path by non pmd threads. This overhead
can be avoided by handling the upcalls directly in pmd threads (a change that
has already been proposed by Ryan Wilson)
Also, the following two fixes have been introduced:
- In dpdk_free_buf() use rte_pktmbuf_free_seg() instead of rte_mempool_put().
This allows OVS to run properly with CONFIG_RTE_LIBRTE_MBUF_DEBUG DPDK option
- Do not bulk free mbufs in a transmission queue. They may belong to different
mempools
Signed-off-by: Daniele Di Proietto <ddiproietto@vmware.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Open vSwitch <http://openvswitch.org>
What is Open vSwitch?
---------------------
Open vSwitch is a multilayer software switch licensed under the open
source Apache 2 license. Our goal is to implement a production
quality switch platform that supports standard management interfaces
and opens the forwarding functions to programmatic extension and
control.
Open vSwitch is well suited to function as a virtual switch in VM
environments. In addition to exposing standard control and visibility
interfaces to the virtual networking layer, it was designed to support
distribution across multiple physical servers. Open vSwitch supports
multiple Linux-based virtualization technologies including
Xen/XenServer, KVM, and VirtualBox.
The bulk of the code is written in platform-independent C and is
easily ported to other environments. The current release of Open
vSwitch supports the following features:
* Standard 802.1Q VLAN model with trunk and access ports
* NIC bonding with or without LACP on upstream switch
* NetFlow, sFlow(R), and mirroring for increased visibility
* QoS (Quality of Service) configuration, plus policing
* Geneve, GRE, GRE over IPSEC, VXLAN, and LISP tunneling
* 802.1ag connectivity fault management
* OpenFlow 1.0 plus numerous extensions
* Transactional configuration database with C and Python bindings
* High-performance forwarding using a Linux kernel module
The included Linux kernel module supports Linux 2.6.32 and up, with
testing focused on 2.6.32 with Centos and Xen patches. Open vSwitch
also has special support for Citrix XenServer and Red Hat Enterprise
Linux hosts.
Open vSwitch can also operate, at a cost in performance, entirely in
userspace, without assistance from a kernel module. This userspace
implementation should be easier to port than the kernel-based switch.
It is considered experimental.
What's here?
------------
The main components of this distribution are:
* ovs-vswitchd, a daemon that implements the switch, along with
a companion Linux kernel module for flow-based switching.
* ovsdb-server, a lightweight database server that ovs-vswitchd
queries to obtain its configuration.
* ovs-dpctl, a tool for configuring the switch kernel module.
* Scripts and specs for building RPMs for Citrix XenServer and Red
Hat Enterprise Linux. The XenServer RPMs allow Open vSwitch to
be installed on a Citrix XenServer host as a drop-in replacement
for its switch, with additional functionality.
* ovs-vsctl, a utility for querying and updating the configuration
of ovs-vswitchd.
* ovs-appctl, a utility that sends commands to running Open
vSwitch daemons.
Open vSwitch also provides some tools:
* ovs-ofctl, a utility for querying and controlling OpenFlow
switches and controllers.
* ovs-pki, a utility for creating and managing the public-key
infrastructure for OpenFlow switches.
* A patch to tcpdump that enables it to parse OpenFlow messages.
What other documentation is available?
--------------------------------------
To install Open vSwitch on a regular Linux or FreeBSD host, please
read INSTALL. For specifics around installation on a specific
platform, please see one of these files:
- INSTALL.Debian
- INSTALL.Fedora
- INSTALL.RHEL
- INSTALL.XenServer
To use Open vSwitch...
- ...with KVM on Linux, read INSTALL, read INSTALL.KVM.
- ...with Libvirt, read INSTALL.Libvirt.
- ...without using a kernel module, read INSTALL.userspace.
For answers to common questions, read FAQ.
To learn how to set up SSL support for Open vSwitch, read INSTALL.SSL.
To learn about some advanced features of the Open vSwitch software
switch, read the tutorial in tutorial/Tutorial.
Each Open vSwitch userspace program is accompanied by a manpage. Many
of the manpages are customized to your configuration as part of the
build process, so we recommend building Open vSwitch before reading
the manpages.
Contact
-------
bugs@openvswitch.org
http://openvswitch.org/