Both mega flow mask's reference counter and per flow table mask list
should only be accessed when holding ovs_mutex() lock. However
this is not true with ovs_flow_table_flush(). The patch fixes this bug.
Reported-by: NJoe Stringer <joestringer@nicira.com>
Signed-off-by: NAndy Zhou <azhou@nicira.com>
Signed-off-by: NJesse Gross <jesse@nicira.com>

With mega flow implementation ovs flow can be shared between
multiple CPUs which makes stats updates highly contended
operation. This patch uses per-CPU stats in cases where a flow
is likely to be shared (if there is a wildcard in the 5-tuple
and therefore likely to be spread by RSS). In other situations,
it uses the current strategy, saving memory and allocation time.
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NJesse Gross <jesse@nicira.com>

API changes only for code readability. No functional chnages.

This patch removes the underscored version. Added a new API
ovs_flow_tbl_lookup_stats() that returns the n_mask_hits.

Reported by: Ben Pfaff <blp@nicira.com>
Reviewed-by: NThomas Graf <tgraf@redhat.com>
Signed-off-by: NAndy Zhou <azhou@nicira.com>
Signed-off-by: NJesse Gross <jesse@nicira.com>

Collect mega flow mask stats. ovs-dpctl show command can be used to
display them for debugging and performance tuning.
Signed-off-by: NAndy Zhou <azhou@nicira.com>
Signed-off-by: NJesse Gross <jesse@nicira.com>

Hides mega-flow implementation in flow_table.c rather than
datapath.c.
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NJesse Gross <jesse@nicira.com>

ovs-flow rehash does not touch mega flow list. Following patch
moves it dp struct datapath.  Avoid one extra indirection for
accessing mega-flow list head on every packet receive.
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NJesse Gross <jesse@nicira.com>

Over the time datapath.c and flow.c has became pretty large files.
Following patch restructures functionality of component into three
different components:

flow.c: contains flow extract.
flow_netlink.c: netlink flow api.
flow_table.c: flow table api.

This patch restructures code without changing logic.
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>
Signed-off-by: NJesse Gross <jesse@nicira.com>