Jarno Rajahalme reported up to 40% performance gain on netperf TCP_CRR with
an earlier version of this patch in combination with a kernel NUMA patch,
together with a reduction in variance:
http://openvswitch.org/pipermail/dev/2014-January/035867.html
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>
Add a prefix tree (trie) structure for tracking the used address
space, enabling skipping classifier tables containing longer masks
than necessary for an address field value in a packet header being
classified. This enables less unwildcarding for datapath flows in
parts of the address space without host routes.
Trie lookup is interwoven to the staged lookup, so that a trie is
searched only when the configured trie field becomes relevant
for the lookup. The trie lookup results are retained so that each
trie is checked at most once for each classifier lookup.
This implementation tracks the number of rules at each address prefix
for the whole classifier. More aggressive table skipping would be
possible by maintaining lists of tables that have prefixes at the
lengths encountered on tree traversal, or by maintaining separate
tries for subsets of rules separated by metadata fields.
Prefix tracking is configured via OVSDB. A new column "prefixes" is
added to the database table "Flow_Table". "prefixes" is a set of
string values listing the field names for which prefix lookup should
be used.
As of now, the fields for which prefix lookup can be enabled are:
- tun_id, tun_src, tun_dst
- nw_src, nw_dst (or aliases ip_src and ip_dst)
- ipv6_src, ipv6_dst
There is a maximum number of fields that can be enabled for any one
flow table. Currently this limit is 3.
Examples:
ovs-vsctl set Bridge br0 flow_tables:0=@N1 -- \
--id=@N1 create Flow_Table name=table0
ovs-vsctl set Bridge br0 flow_tables:1=@N1 -- \
--id=@N1 create Flow_Table name=table1
ovs-vsctl set Flow_Table table0 prefixes=ip_dst,ip_src
ovs-vsctl set Flow_Table table1 prefixes=[]
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
Subtable lookup is performed in ranges defined for struct flow,
starting from metadata (registers, in_port, etc.), then L2 header, L3,
and finally L4 ports. Whenever it is found that there are no matches
in the current subtable, the rest of the subtable can be skipped. The
rationale of this logic is that as many fields as possible can remain
wildcarded.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
The naming of the classifier table has been a source of confusion,
since each OpenFlow table is implemented as a classifier, which
consists of multiple (sub)tables. This name change hopefully makes
classifier related discussion a bit less confusing.
For consistency, relevant field names as well as the function and
variable names have been renamed in similar fashion.
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
It's easy to add two tags together, but it's hard to subtract them. The
new "tag_tracker" data structure provides a solution.
Signed-off-by: Ben Pfaff <blp@nicira.com>
We have a controller that puts many rules with different metadata values
into the flow table, where metadata is used (by "resubmit"s) to distinguish
stages in a pipeline. Thus, any given flow only needs to be hashed into
classifier "cls_table"s that contain a match for the flow's metadata value.
This commit optimizes the classifier lookup by (probabilistically) skipping
the "cls_table"s that can't possibly match.
(The "metadata" referred to here is the OpenFlow 1.1+ "metadata" field,
which is a 64-bit field similar in purpose to the "registers" defined by
Open vSwitch.)
Previous versions of this patch, with earlier versions of the controller in
question, improved flow setup performance by about 19%.
Bug #14282.
Signed-off-by: Ben Pfaff <blp@nicira.com>
A future commit will want to know what bits were significant during the
classifier lookup.
Signed-off-by: Ethan Jackson <ethan@nicira.com>
Co-authored-by: Justin Pettit <jpettit@nicira.com>
Signed-off-by: Justin Pettit <jpettit@nicira.com>
Signed-off-by: Jarno Rajahalme <jarno.rajahalme@nsn.com>
[blp@nicira.com: this along with Jarno's previous patch to the
classifier give me a combined 15% boost in "ovs-benchmark rate"
with a complicated flow table involving multiple resubmits]
Signed-off-by: Ben Pfaff <blp@nicira.com>
This is a straight search-and-replace, except that I also removed #include
<assert.h> from each file where there were no assert calls left.
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>
The open-coded version of destroy_table() in classifier_destroy() didn't
free the table's minimatch. Use destroy_table() to do it properly.
This is only a theoretical leak because all the existing callers actually
remove all the rules from their classifiers before they destroy them
(outside of the tests/ directory, which I didn't examine) and so they don't
ever have anything left to remove in classifier_destroy().
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>
A cls_rule is 324 bytes on i386 now. The cost of a flow table lookup is
currently proportional to this size, which is going to continue to grow.
However, the required cost of a flow table lookup, with the classifier that
we currently use, is only proportional to the number of bits that a rule
actually matches. This commit implements that optimization by replacing
the match inside "struct cls_rule" by a sparse representation.
This reduces struct cls_rule to 100 bytes on i386.
There is still some headroom for further optimization following this
commit:
- I suspect that adding an 'n' member to struct miniflow would make
miniflow operations faster, since popcount() has some cost.
- It's probably possible to replace the "struct minimatch" in cls_rule
by just a "struct miniflow", since the cls_rule's cls_table has a
copy of the minimask.
- Some of the miniflow operations aren't well-optimized.
Signed-off-by: Ben Pfaff <blp@nicira.com>
When cls_cursor_init() is given a NULL target, it can skip an expensive
step comparing the rule against the target for every table and every rule
in the classifier. collect_rule_loose() and other callers could take
advantage of this optimization, except that they actually pass in a rule
that matches everything instead of a NULL rule (e.g. for "ovs-ofctl
dump-flows <bridge>" without specifying a matching rule).
This optimizes that case.
Signed-off-by: Ben Pfaff <blp@nicira.com>
Until now, "struct cls_rule" didn't own any data outside its own memory
block. An upcoming commit will make "struct cls_rule" sometimes own blocks
of memory, so it needs "destroy" and to a lesser extent "clone" functions.
This commit adds these in advance, even though they are mostly no-ops, to
make it possible to separately review the memory management.
Signed-off-by: Ben Pfaff <blp@nicira.com>
Now that "struct flow" and "struct flow_wildcards" have the same simple
and uniform structure, it's easy to handle common operations by just
iterating over the bits inside them.
Signed-off-by: Ben Pfaff <blp@nicira.com>
OpenFlow 1.0 and 1.2 have notions of VLAN that are different
enough to warrant separate "meta-flow" fields, which this commit
adds.
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Simon Horman <horms@verge.net.au>
This function is specific to the OF1.0 dl_vlan field, so name it
consistently.
Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Simon Horman <horms@verge.net.au>
[blp@nicira.com added NEWS, updated a few overlooked meta-flow bits]
Signed-off-by: Ben Pfaff <blp@nicira.com>
Add helpers for setting ethernet addresses.
This patch makes use of them for setting the dl_src and dl_dst
addresses. A subsequent patch will also use them for arp_sha and arp_tpa.
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Ben Pfaff <blp@nicira.com>
* Remove duplicate definition of OFP_VLAN_NONE
* Rename OFP_VLAN_NONE as OFP10_VLAN_NONE as it appears to be
only used by OpenFlow 1.0.
As suggested by Ben Pfaff.
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Ben Pfaff <blp@nicira.com>
It turns out that eth_addr_equal_except() computed the exact
opposite of what it purported to. It returned true if the two
arguments where *not* equal. This is extremely confusing, so this
patch changes it.
Signed-off-by: Ethan Jackson <ethan@nicira.com>
Arbitrary ethernet mask support is one step on the way to support for OpenFlow
1.1+. This patch set seeks to add this capability without breaking current
protocol support.
Signed-off-by: Joe Stringer <joe@wand.net.nz>
[blp@nicira.com made some updates, see
http://openvswitch.org/pipermail/dev/2012-May/017585.html]
Signed-off-by: Ben Pfaff <blp@nicira.com>
Replaced all instances of Nicira Networks(, Inc) to Nicira, Inc.
Feature #10593
Signed-off-by: Raju Subramanian <rsubramanian@nicira.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>
Most flow tables have some kind of "catchall" rule that matches every
packet. For this table, the cost of copying, zeroing, and hashing the
input flow is significant. This patch avoids these costs.
Signed-off-by: Ben Pfaff <blp@nicira.com>
This priority's mean is completely different from the priority of an
OpenFlow rule, so it is confusing for it to have the same name.
We should be on the lookout for a less Linux-specific name, but this one
seems fine for now.
Signed-off-by: Ben Pfaff <blp@nicira.com>
It's no longer necessary to maintain a "nw_tos_mask" wildcard member,
since we only care about completely wildcarding the DSCP and ECN
portions of the IP TOS field. This commit makes that change. It also
goes a bit further in internally using "tos" to refer to the entire TOS
field (ie, DSCP and ECN). We must still refer to the DSCP portions as
"nw_tos" externally through OpenFlow 1.0, since that's the convention it
uses.
The meta-flow code enforces IPv4/IPv6 masks, so there's no reason to do
it again in the classifier. This allows a number of functions to be
removed, since the only callers were in this classifier code.
Most of the members in structures referring to network elements indicate
the layer (e.g., "tl_", "nw_", "tp_"). The "frag" and "tos" members
didn't, so this commit add them.
Add support matching the IPv4 TTL and IPv6 hop limit fields. This
commit also adds support for modifying the IPv4 TTL. Modifying the IPv6
hop limit isn't currently supported, since we don't support modifying
IPv6 headers.
We will likely want to change the user-space interface, since basic
matching and setting the TTL are not generally useful. We will probably
want the ability to match on extraordinary events (such as TTL of 0 or 1)
and a decrement action.
Feature #8024
Signed-off-by: Justin Pettit <jpettit@nicira.com>
Acked-by: Jesse Gross <jesse@nicira.com>
