Hi We applied your suggestion of removing the `IsLinkUp()` call. But the performace is even worse. We could only get around 340kbits/s.
The Top Hotspots are: Function Module CPU Time eth_em_recv_pkts librte_pmd_e1000.so 15.106s rte_delay_us_block librte_eal.so.6.1 7.372s ns3::DpdkNetDevice::Read libns3.28.1-fd-net-device-debug.so 5.080s rte_eth_rx_burst libns3.28.1-fd-net-device-debug.so 3.558s ns3::DpdkNetDeviceReader::DoRead libns3.28.1-fd-net-device-debug.so 3.364s [Others] 4.760s Upon checking the callers of `rte_delay_us_block`, we got to know that most of the time (92%) spent in this function is during initialization. This does not waste our processing time during communication. So, it's a good start to our optimization. Callers CPU Time: Total CPU Time: Self rte_delay_us_block 100.0% 7.372s e1000_enable_ulp_lpt_lp 92.3% 6.804s e1000_write_phy_reg_mdic 1.8% 0.136s e1000_reset_hw_ich8lan 1.7% 0.128s e1000_read_phy_reg_mdic 1.4% 0.104s eth_em_link_update 1.4% 0.100s e1000_get_cfg_done_generic 0.7% 0.052s e1000_post_phy_reset_ich8lan.part.18 0.7% 0.048s Effective CPU Utilization: 21.4% (0.856 out of 4) Here is the link to vtune profiling results. https://drive.google.com/open?id=1M6g2iRZq2JGPoDVPwZCxWBo7qzUhvWi5 Thank you Regards On Sun, Dec 30, 2018, 06:00 Wiles, Keith <[email protected]> wrote: > > > > On Dec 29, 2018, at 4:03 PM, Harsh Patel <[email protected]> > wrote: > > > > Hello, > > As suggested, we tried profiling the application using Intel VTune > Amplifier. We aren't sure how to use these results, so we are attaching > them to this email. > > > > The things we understood were 'Top Hotspots' and 'Effective CPU > utilization'. Following are some of our understandings: > > > > Top Hotspots > > > > Function Module CPU Time > > rte_delay_us_block librte_eal.so.6.1 15.042s > > eth_em_recv_pkts librte_pmd_e1000.so 9.544s > > ns3::DpdkNetDevice::Read libns3.28.1-fd-net-device-debug.so > 3.522s > > ns3::DpdkNetDeviceReader::DoRead > libns3.28.1-fd-net-device-debug.so 2.470s > > rte_eth_rx_burst libns3.28.1-fd-net-device-debug.so 2.456s > > [Others] 6.656s > > > > We knew about other methods except `rte_delay_us_block`. So we > investigated the callers of this method: > > > > Callers Effective Time Spin Time Overhead Time Effective Time > Spin Time Overhead Time Wait Time: Total Wait Time: Self > > e1000_enable_ulp_lpt_lp 45.6% 0.0% 0.0% 6.860s 0usec 0usec > > e1000_write_phy_reg_mdic 32.7% 0.0% 0.0% 4.916s 0usec > 0usec > > e1000_read_phy_reg_mdic 19.4% 0.0% 0.0% 2.922s 0usec 0usec > > e1000_reset_hw_ich8lan 1.0% 0.0% 0.0% 0.143s 0usec 0usec > > eth_em_link_update 0.7% 0.0% 0.0% 0.100s 0usec 0usec > > e1000_post_phy_reset_ich8lan.part.18 0.4% 0.0% 0.0% 0.064s > 0usec 0usec > > e1000_get_cfg_done_generic 0.2% 0.0% 0.0% 0.037s 0usec > 0usec > > > > We lack sufficient knowledge to investigate more than this. > > > > Effective CPU utilization > > > > Interestingly, the effective CPU utilization was 20.8% (0.832 out of 4 > logical CPUs). We thought this is less. So we compared this with the > raw-socket version of the code, which was even less, 8.0% (0.318 out of 4 > logical CPUs), and even then it is performing way better. > > > > It would be helpful if you give us insights on how to use these results > or point us to some resources to do so. > > > > Thank you > > > > BTW, I was able to build ns3 with DPDK 18.11 it required a couple changes > in the DPDK init code in ns3 plus one hack in rte_mbuf.h file. > > I did have a problem including rte_mbuf.h file into your code. It appears > the g++ compiler did not like referencing the struct rte_mbuf_sched inside > the rte_mbuf structure. The rte_mbuf_sched was inside the big union as a > hack I moved the struct outside of the rte_mbuf structure and replaced the > struct in the union with ’struct rte_mbuf_sched sched;', but I am guessing > you are missing some compiler options in your build system as DPDK builds > just fine without that hack. > > The next place was the rxmode and the txq_flags. The rxmode structure has > changed and I commented out the inits in ns3 and then commented out the > txq_flags init code as these are now the defaults. > > Regards, > Keith > >
