Re: [PATCH] vhost: try to shrink pfdset when fdset_add fails

On Wed, Feb 22, 2017 at 11:01:43AM +0100, Matthias Gatto wrote:

On Wed, Feb 22, 2017 at 2:59 AM, Yuanhan Liu
[off-list ref] wrote:

quoted

On Tue, Feb 21, 2017 at 03:25:30PM +0100, Matthias Gatto wrote:

quoted

fdset_add increment pfdset->num, but fdset_del doesn't decrement pfdset->num,
so if we call fdset_add then fdset_del in a loop witout calling
fdset_shrink, we can easily exceed MAX_FDS with only a few number of fds
used.

I'm assuming you were doing some tests like following?

        while true; do
                ovs-vsctl add-port br vhost_n -- ...
                ovs-vsctl del-port vhost_n
        done

Something pretty close to this yes.

    Fixes: 59317cef249c ("vhost: allow many vhost-user ports")
    
    Cc: stable@dpdk.org

And applied to dpdk-next-virtio, with few typos in commit log fixed.

Thanks!

	--yliu