On 12.12.2017 15:31, Eelco Chaudron wrote: > On 11/12/17 17:31, Ilya Maximets wrote: >> Added information about output packet batching and a way to >> configure 'tx-flush-interval'. >> >> Signed-off-by: Ilya Maximets <[email protected]> >> --- >> >> This patch is made on top of v7 of Output Batching patch-set: >> >> https://mail.openvswitch.org/pipermail/ovs-dev/2017-December/341936.html >> >> This patch sent as RFC separately from the rest of the series because >> it's new and I don't want this to block accepting of the main series. >> It'll be much easier to fix/rebase just this patch without re-sending >> of the whole patch-set. >> >> Documentation/intro/install/dpdk.rst | 24 ++++++++++++++++++++++++ >> 1 file changed, 24 insertions(+) >> >> diff --git a/Documentation/intro/install/dpdk.rst >> b/Documentation/intro/install/dpdk.rst >> index 3fecb5c..b0bb76e 100644 >> --- a/Documentation/intro/install/dpdk.rst >> +++ b/Documentation/intro/install/dpdk.rst >> @@ -568,6 +568,30 @@ not needed i.e. jumbo frames are not needed, it can be >> forced off by adding >> chains of descriptors it will make more individual virtio descriptors >> available >> for rx to the guest using dpdkvhost ports and this can improve performance. >> +Output Packet Batching >> +~~~~~~~~~~~~~~~~~~~~~~ >> + > See some _XYZ_ remarks below, but I guess a native speaker might be better at > this...
Thanks. I'm not a native speaker either. Therefore, any grammar / wording corrections are welcome. >> +To get advantages of _THE_ batched send functions OVS collects packets in >> +intermediate queues before sending. This allows _USING_ _A_ single send for >> +packets matched by different flows but having _THE_ same output action. >> Furthermore, >> +OVS is able to collect packets for some reasonable amount of time before >> +_BATCH_ sending _THEM_ _WHICH MIGHT HELP WHEN_ input batches are small. >> + >> +``tx-flush-interval`` config could be used to specify the time in >> microseconds >> +that a packet can wait in an output queue for sending (default is ``0``):: >> + >> + $ ovs-vsctl set Open_vSwitch . other_config:tx-flush-interval=50 >> + >> +Lower values _DECREASE_ latency while higher values may be useful to achieve >> +higher performance. For example, increasing of ``tx-flush-interval`` can be >> +used to decrease _THE_ number of interrupts for interrupt based guest >> drivers. >> +This may significantly affect the performance. Zero value means immediate >> +send at the end of processing _DEL_of_ a single input batch. >> + >> +Average number of packets per output batch could be checked in PMD stats:: >> + >> + $ ovs-appctl dpif-netdev/pmd-stats-show >> + >> Limitations >> ------------ _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
