"dev" <[email protected]> wrote on 05/12/2016 08:43:10 AM:
> From: Ilya Maximets <[email protected]> > To: [email protected], Daniele Di Proietto <[email protected]> > Cc: Dyasly Sergey <[email protected]>, Flavio Leitner > <[email protected]>, Ilya Maximets <[email protected]>, Kevin > Traynor <[email protected]> > Date: 05/12/2016 08:44 AM > Subject: [ovs-dev] [PATCH RFC 1/6] netdev-dpdk: Use instant sending > instead of queueing of packets. > Sent by: "dev" <[email protected]> > > Current implementarion of TX packet's queueing is broken in several ways: > > * TX queue flushing implemented on receive assumes that all > core_id-s are sequential and starts from zero. This may lead > to situation when packets will stuck in queue forever and, > also, this influences on latency. > > * For a long time flushing logic depends on uninitialized > 'txq_needs_locking', because it usually calculated after > 'netdev_dpdk_alloc_txq' but used inside of this function > for initialization of 'flush_tx'. > > According to current flushing logic, constant flushing required if TX > queues will be shared among different CPUs. Further patches will implement > mechanisms for manipulations with TX queues in runtime. In this case PMD > threads will not know is current queue shared or not. This means that > constant flushing will be required. > > Conclusion: Lets remove queueing at all because it doesn't work > properly now and, also, constant flushing required anyway. > > Testing on basic PHY-OVS-PHY and PHY-OVS-VM-OVS-PHY scenarios shows > insignificant performance drop (less than 0.5 percents) in compare to > profit that we can achieve in the future using XPS or other features. > > Signed-off-by: Ilya Maximets <[email protected]> > --- I know this has an acked-by, but when I rechecked this morning, hunk #7 fails to apply - it looks like a one line delta, so I manually patched around it to check the rest of the series and consider this an FYI to whomever goes to push this. Ryan _______________________________________________ dev mailing list [email protected] http://openvswitch.org/mailman/listinfo/dev
