On Wed, Sep 26, 2018 at 2:58 AM Stefano Brivio <sbri...@redhat.com> wrote: > > Hi Pravin, > > On Wed, 15 Aug 2018 00:19:39 -0700 > Pravin Shelar <pshe...@ovn.org> wrote: > > > I understand fairness has cost, but we need to find right balance > > between performance and fairness. Current fairness scheme is a > > lockless algorithm without much computational overhead, did you try to > > improve current algorithm so that it uses less number of ports. > > In the end, we tried harder as you suggested, and found out a way to > avoid the need for per-thread sets of per-vport sockets: with a few > changes, a process-wide set of per-vport sockets is actually enough to > maintain the current fairness behaviour. > > Further, we can get rid of duplicate fd events if the EPOLLEXCLUSIVE > epoll() flag is available, which improves performance noticeably. This > is explained in more detail in the commit message of the ovs-vswitchd > patch Matteo wrote [1], now merged. > > This approach solves the biggest issue (i.e. huge amount of netlink > sockets) in ovs-vswitchd itself, without the need for kernel changes. >
Thanks for working on this issue. > It doesn't address some proposed improvements though, that is, it does > nothing to improve the current fairness scheme, it won't allow neither > the configurable fairness criteria proposed by Ben, nor usage of BPF > maps for extensibility as suggested by William. > > I would however say that those topics bear definitely lower priority, > and perhaps addressing them at all becomes overkill now that we don't > any longer have a serious issue. > > [1] https://patchwork.ozlabs.org/patch/974304/ Nice! Thanks, Pravin.
