[ovs-git] Open vSwitch: netlink-socket: Increase Netlink socket receive buffer size. (master)

dev at openvswitch.org dev at openvswitch.org
Fri Mar 16 04:44:35 UTC 2012


This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "Open vSwitch".

The branch, master has been updated
       via  d2b9f5b017df990087cd00fe5f195b829c243b73 (commit)
      from  33500edd53fd76a304766812fd0829e7f3ab222f (commit)

Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.

- Log -----------------------------------------------------------------
commit d2b9f5b017df990087cd00fe5f195b829c243b73
Diffs: http://openvswitch.org/cgi-bin/gitweb.cgi?p=openvswitch;a=commitdiff;h=d2b9f5b017df990087cd00fe5f195b829c243b73
Author: Ben Pfaff <blp at nicira.com>
		
netlink-socket: Increase Netlink socket receive buffer size.
		
Open vSwitch userspace can set up flows at a high rate, but it is somewhat
"bursty" in opportunities to set up flows, by which I mean that OVS sets up
a batch of flows, then goes off and does some other work for a while, then
sets up another batch of flows, and so on.  The result is that, if a large
number of packets that need flow setups come in all at once, then some of
them can overflow the relatively small kernel-to-user buffers.

This commit increases the kernel-to-user buffers from the default of
approximately 120 kB each to 1 MB each.  In one somewhat synthetic test
case that I ran based on an "hping3" that generated a load of about 20,000
new flows per second (including both requests and replies), this reduced
the packets dropped at the kernel-to-user interface from about 30% to none.
I expect that it will similarly improve packet loss in workloads where
flow arrival is not easily predictable.

(This has little effect on workloads generated by "ovs-benchmark rate"
because that benchmark is effectively "self-clocking", that is, a new flow
is triggered only by a reply to a request made earlier, which means that
the number of buffered packets at any given has a known, constant upper
limit.)

Bug #10210.
Signed-off-by: Ben Pfaff <blp at nicira.com>


-----------------------------------------------------------------------

Summary of changes:
 include/sparse/sys/socket.h |    5 +++--
 lib/netlink-socket.c        |   10 +++++++++-
 2 files changed, 12 insertions(+), 3 deletions(-)


hooks/post-receive
-- 
Open vSwitch



More information about the git mailing list