[ovs-dev] [poll group RFC 0/6] poll group RFC

[Andy Zhou]

On Thu, Feb 18, 2016 at 8:20 PM, Andy Zhou <azhou at ovn.org> wrote:

> This is the new 'poll group' feature I have been working on improve
> the efficiency in dealing with large number of connections, and its
> first application to improve ovsdb-sever.
>
> There is a known limitation:
>
> The probing feature does not work properly. Poll group avoids
> waking up a connection if there is no active I/O going on. An inactive
> session won't send out probes. Timed wake up currently bypass those
> connections per design.  I can think of a few options to improve / restore
> this feature if necessary. In the mean time, the TCP keep alive option,
> suggested on OVN IRC channel also looks attractive.
>

I have since figured out what the problem was. Poll_block() can be waken
either by fd events or by time out. Sessions joined poll group should still
be visited
if it was time out.  I have reposted the series with the fix.   IMHO, TCP
keep alive
may still be worth looking into.