[ovs-dev] 100% CPU in ovs-vswitchd (again)

[Ben Pfaff]

It's not the first time we've had this kind of bug.  Last time, I
tried to think of a good unit test, but did not succeed.

On Tue, Sep 30, 2014 at 10:32:15AM -0700, Alex Wang wrote:
> I can reproduce it, working on a fix,
> 
> Thx for reporting~
> 
> On Tue, Sep 30, 2014 at 9:37 AM, Ben Pfaff <blp at nicira.com> wrote:
> 
> > There's still a 100% CPU bug in ovs-vswitchd.  Run "make sandbox", then
> > run a second ovs-vswitchd inside the subshell (just run a bare
> > "ovs-vswitchd" without any parameters).  You get output like this:
> >
> >     2014-09-30T16:33:45Z|00001|ovs_numa|INFO|Discovered 8 CPU cores on
> > NUMA node 0
> >     2014-09-30T16:33:45Z|00002|ovs_numa|INFO|Discovered 1 NUMA nodes and 8
> > CPU cores
> >
> > 2014-09-30T16:33:45Z|00003|reconnect|INFO|unix:/home/blp/nicira/ovs/tutorial/sandbox/db.sock:
> > connecting...
> >
> > 2014-09-30T16:33:45Z|00004|reconnect|INFO|unix:/home/blp/nicira/ovs/tutorial/sandbox/db.sock:
> > connected
> >     2014-09-30T16:33:45Z|00005|bridge|ERR|another ovs-vswitchd process is
> > running, disabling this process (pid 13812) until it goes away
> >     2014-09-30T16:33:48Z|00006|poll_loop|INFO|wakeup due to 1-ms timeout
> > at ../vswitchd/bridge.c:2723 (100% CPU usage)
> >     2014-09-30T16:33:48Z|00007|poll_loop|INFO|wakeup due to 0-ms timeout
> > at ../vswitchd/bridge.c:2723 (100% CPU usage)
> >     2014-09-30T16:33:48Z|00008|poll_loop|INFO|wakeup due to 0-ms timeout
> > at ../vswitchd/bridge.c:2723 (100% CPU usage)
> >     2014-09-30T16:33:48Z|00009|poll_loop|INFO|wakeup due to 0-ms timeout
> > at ../vswitchd/bridge.c:2723 (100% CPU usage)
> >     2014-09-30T16:33:48Z|00010|poll_loop|INFO|wakeup due to 0-ms timeout
> > at ../vswitchd/bridge.c:2723 (100% CPU usage)
> >     2014-09-30T16:33:48Z|00011|poll_loop|INFO|wakeup due to 0-ms timeout
> > at ../vswitchd/bridge.c:2723 (100% CPU usage)
> >     2014-09-30T16:33:48Z|00012|poll_loop|INFO|wakeup due to 0-ms timeout
> > at ../vswitchd/bridge.c:2723 (100% CPU usage)
> >     2014-09-30T16:33:48Z|00013|poll_loop|INFO|wakeup due to 0-ms timeout
> > at ../vswitchd/bridge.c:2723 (100% CPU usage)
> >     2014-09-30T16:33:48Z|00014|poll_loop|INFO|wakeup due to 0-ms timeout
> > at ../vswitchd/bridge.c:2723 (100% CPU usage)
> >     2014-09-30T16:33:48Z|00015|poll_loop|INFO|wakeup due to 0-ms timeout
> > at ../vswitchd/bridge.c:2723 (100% CPU usage)
> >
> > The cited line in bridge.c is:
> >
> >         seq_wait(connectivity_seq_get(), connectivity_seqno);
> >
> > Thanks,
> >
> > Ben.
> >