upcall: Cache the number of flows from the datapath.
authorJoe Stringer <joestringer@nicira.com>
Wed, 22 Jan 2014 06:50:49 +0000 (06:50 +0000)
committerEthan Jackson <ethan@nicira.com>
Tue, 21 Jan 2014 23:39:31 +0000 (15:39 -0800)
commit64ca9472f0b0f40b94abe2adf5d397bdf3d5e7b3
treec608a5d8252da62026ee95194932436195b17e03
parentdfe37e6abd276de01f686bbdf28cbf48e92cd1dc
upcall: Cache the number of flows from the datapath.

Fetching the number of flows in the datapath has been causing
unnecessary contention on the kernel ovs_lock in recent TCP CRR tests.
This patch caches this number for up to 100ms in the userspace to reduce
such kernel calls.

Signed-off-by: Joe Stringer <joestringer@nicira.com>
Co-authored-by: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off--by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>
ofproto/ofproto-dpif-upcall.c