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| author |   Joe Stringer <joestringer@nicira.com> | 2015-01-21 16:42:52 -0800 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2015-01-26 15:45:50 -0800 |
| commit | 74ed7ab9264c54471c7f057409d352052820d750 (patch) | |
| tree | f90152a0560337fceaf55538a9e57e8c9aaa9182 /Documentation/networking | |
| parent | genetlink: Add genlmsg_parse() helper function. (diff) | |
| download | linux-dev-74ed7ab9264c54471c7f057409d352052820d750.tar.xz linux-dev-74ed7ab9264c54471c7f057409d352052820d750.zip | |
openvswitch: Add support for unique flow IDs.
Previously, flows were manipulated by userspace specifying a full,
unmasked flow key. This adds significant burden onto flow
serialization/deserialization, particularly when dumping flows.
This patch adds an alternative way to refer to flows using a
variable-length "unique flow identifier" (UFID). At flow setup time,
userspace may specify a UFID for a flow, which is stored with the flow
and inserted into a separate table for lookup, in addition to the
standard flow table. Flows created using a UFID must be fetched or
deleted using the UFID.
All flow dump operations may now be made more terse with OVS_UFID_F_*
flags. For example, the OVS_UFID_F_OMIT_KEY flag allows responses to
omit the flow key from a datapath operation if the flow has a
corresponding UFID. This significantly reduces the time spent assembling
and transacting netlink messages. With all OVS_UFID_F_OMIT_* flags
enabled, the datapath only returns the UFID and statistics for each flow
during flow dump, increasing ovs-vswitchd revalidator performance by 40%
or more.
Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation/networking')
| -rw-r--r-- | Documentation/networking/openvswitch.txt | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/Documentation/networking/openvswitch.txt b/Documentation/networking/openvswitch.txt index 37c20ee2455e..b3b9ac61d29d 100644 --- a/Documentation/networking/openvswitch.txt +++ b/Documentation/networking/openvswitch.txt @@ -131,6 +131,19 @@ performs best-effort detection of overlapping wildcarded flows and may reject some but not all of them. However, this behavior may change in future versions. +Unique flow identifiers +----------------------- + +An alternative to using the original match portion of a key as the handle for +flow identification is a unique flow identifier, or "UFID". UFIDs are optional +for both the kernel and user space program. + +User space programs that support UFID are expected to provide it during flow +setup in addition to the flow, then refer to the flow using the UFID for all +future operations. The kernel is not required to index flows by the original +flow key if a UFID is specified. + + Basic rule for evolving flow keys --------------------------------- |