ofproto: RCU postpone rule destruction.

This allows rules to be used without taking references while RCU
protected.

The last step of destroying an ofproto also needs to be postponed, as
the rule destruction requires the class structure to be available at
the postponed destruction callback.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>
ofproto: Make taking rule reference conditional on lookup.

Prior to this paths the rule lookup functions have always taken a
reference on the found rule before returning.  Make this conditional,
so that unnecessary refs/unrefs can be avoided in a later patch.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>
ofproto: Reduce taking rule references.

Only take reference to a looked up rule when needed.

This reduces the total CPU utilization of rule_ref/unref calls by 80%,
from 5% of total server CPU capacity to 1% in a netperf TCP_CRR
test stressing the userspace.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>
ofproto-dpif-xlate: Identify STP BPDUs more specifically.

Apart from STP, EVB extension of LLDP as well as IEEE 802.1QBG use the
Nearest Customer Bridge (NCB) DMAC which has a value of 0180.c200.0000.
STP can be distinguished by Ethertype from these protocols.

Signed-off-by: Padmanabhan Krishnan <kprad1@yahoo.com>
[blp@nicira.com rewrote the details of the patch]
Signed-off-by: Ben Pfaff <blp@nicira.com>
Tested-by: Padmanabhan Krishnan <kprad1@yahoo.com>
daemon: Rename daemon.c as daemon-unix.c

An upcoming commit re-introduces daemon.c to have
common functions across daemon-unix.c and daemon-windows.c

Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
daemon: Close standard file descriptors after detach for windows.

In the unit tests, we check for some logs stored in stderr. In case
of windows, unit tests fail because the child writes additional information
into stderr because it does not have it closed. This commit
closes standard file descriptors for windows too.

Because the functions related to closing file descriptors is common
for both windows and unix, add it to the common daemonization file
daemon.c

Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
daemon: Move some common code to daemon.c

We have some common code between daemon-unix.c and
daemon-windows.c. Move them to daemon.c

Signed-off-by: Gurucharan Shetty <gshetty@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
bfd/cfm: Check status change before update status to database.

This commit adds boolean flag in bfd/cfm module for checking
status change.  If there is no status change, the current
update to OVS database will skip the bfd/cfm session.

In the experiment with 5K bfd sessions, when one session is
flapping at rate of every 0.3 second, this patch reduces the
cpu utilization of the ovs-vswitchd thread from 13 to 6.

Signed-off-by: Alex Wang <alexw@nicira.com>
Acked-by: Joe Stringer <joestringer@nicira.com>
FAQ: Explain what to do when building against a too-new kernel.

Also add references to this FAQ from INSTALL and configure.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Gurucharan Shetty <gshetty@nicira.com>