From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it1-f195.google.com (mail-it1-f195.google.com [209.85.166.195]) by dpdk.org (Postfix) with ESMTP id 70D051B1EB for ; Tue, 5 Feb 2019 15:22:58 +0100 (CET) Received: by mail-it1-f195.google.com with SMTP id m62so8684528ith.5 for ; Tue, 05 Feb 2019 06:22:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=lvrD+8ushjUhXsKJ9pCfoGJd5bqVJn6hCKH5pGQIYak=; b=hNLdkM6SI+dfxjRCDAFvqygLpTUTrgPU7r/X/6sTFzacsERKubKy0ojmzXq7m6fx+H F5OmQaE4vIW0qRf3V8moG99ZOGsqjeVAnorqZ3DTQx3OCaeEc9ds8opWTwp09r2QvZ1S qQ7V2u3NzdMdi8WrsQaYpEtgmgblm8+t4u+GQqK0uqiv2yg7/XeuhPer8tkeZvH0hB2S 7St0VXVSo+Ah5I+UCge0zY+NZaYfCa1pgvvVFUemfuvltxd5RqdhKesClyVnW//iDx5M 2bAcbBwFtYNTIa6isVaoxLwHws8rqispPHFd4xchAtZM/9svge2SjEviA9/rmFVkvaA/ sPXQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=lvrD+8ushjUhXsKJ9pCfoGJd5bqVJn6hCKH5pGQIYak=; b=t7e+OpFiNmwwEBFGF7SC773+lLICSAdESjBdSUbInDseJP/mIakTrpDbcOaHQ5RcxF OGJPnsxZ5HukX+rAFyBkI1YTsYYDO8VZ8PBzNzXT0qHjtEzjloKQLmbAYW91yv7DaLaz pywa8EVu1UkNPhQkgZEaBQmqyZKmcYNFhcDxFCpety4KvjmWXlyNX1QGOljzQolXDOl6 EPwGghl1lHazPvxVVQG2OEtJfDVQ+nuEZ7cLsjRPFcvsn1SD8jhfCTbtI2wC/5VMlBVh NryqCxw0wMfe0jcDF5kY4/OHStYrEbRDZHJ8rvPXpBljcHnvhfDoxTuGmL+Bonzitkxu 13Jw== X-Gm-Message-State: AHQUAuY/7qfZWaCd6HpyZAafyx44Pk6U+rM8ZXlrqexTvuEBt4s7o5Ws ftg2GMqO4dd5bdkbAzWcDLK7kqMWD5i5hff+fQo= X-Google-Smtp-Source: AHgI3IbaG/ryTwHI4fb2Lh7luH/gsgPb9O2m7c0cEmTWHDPBtKPO57ueJ0TQLTDvO16zzmNyo3ZfU8jfaBK+4kJTgcg= X-Received: by 2002:a24:1f0d:: with SMTP id d13mr2476554itd.140.1549376577464; Tue, 05 Feb 2019 06:22:57 -0800 (PST) MIME-Version: 1.0 References: <71CBA720-633D-4CFE-805C-606DAAEDD356@intel.com> <3C60E59D-36AD-4382-8CC3-89D4EEB0140D@intel.com> <76959924-D9DB-4C58-BB05-E33107AD98AC@intel.com> <485F0372-7486-473B-ACDA-F42A2D86EF03@intel.com> <34E92C48-A90C-472C-A915-AAA4A6B5CDE8@intel.com> <20181124203541.4aa9bbf2@xeon-e3> <1B6F92FD-D742-4377-896A-8D7DA6AAF799@intel.com> <72A7DD4D-35FD-4247-805D-E9A736B1C9B6@intel.com> <5F05CD7D-2EAB-476A-99B6-031CF835BA37@intel.com> <05A7519B-28EC-4A34-812E-A50A50F16A8A@intel.com> <514F1920-6C4C-494E-8634-DC60A67642D9@intel.com> In-Reply-To: <514F1920-6C4C-494E-8634-DC60A67642D9@intel.com> From: Harsh Patel Date: Tue, 5 Feb 2019 19:52:43 +0530 Message-ID: To: "Wiles, Keith" Cc: Stephen Hemminger , Kyle Larose , "users@dpdk.org" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-users] Query on handling packets X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 05 Feb 2019 14:22:58 -0000 Can you help us with those questions we asked you? We need them as parameters for our testing. Thanks, Harsh & Hrishikesh On Tue, Feb 5, 2019, 19:42 Wiles, Keith wrote: > > > > On Feb 5, 2019, at 8:00 AM, Harsh Patel > wrote: > > > > Hi, > > One of the mistake was as following. ns-3 frees the packet buffer just > as it writes to the socket and thus we thought that we should also do the > same. But dpdk while writing places the packet buffer to the tx descripto= r > ring and perform the transmission after that on its own. And we were > freeing early so sometimes the packets were lost i.e. freed before > transmission. > > > > Another thing was that as you suggested earlier we compiled the whole > ns-3 in optimized mode. That improved the performance. > > > > These 2 things combined got us the desired results. > > Excellent thanks > > > > Regards, > > Harsh & Hrishikesh > > > > On Tue, Feb 5, 2019, 18:33 Wiles, Keith wrote: > > > > > > > On Feb 5, 2019, at 12:37 AM, Harsh Patel > wrote: > > > > > > Hi, > > > > > > We would like to inform you that our code is working as expected and > we are able to obtain 95-98 Mbps data rate for a 100Mbps application rate= . > We are now working on the testing of the code. Thanks a lot, especially t= o > Keith for all the help you provided. > > > > > > We have 2 main queries :- > > > 1) We wanted to calculate Backlog at the NIC Tx Descriptors but were > not able to find anything in the documentation. Can you help us in how to > calculate the backlog? > > > 2) We searched on how to use Byte Queue Limit (BQL) on the NIC queue > but couldn't find anything like that in DPDK. Does DPDK support BQL? If s= o, > can you help us on how to use it for our project? > > > > what was the last set of problems if I may ask? > > > > > > Thanks & Regards > > > Harsh & Hrishikesh > > > > > > On Thu, 31 Jan 2019 at 22:28, Wiles, Keith > wrote: > > > > > > > > > Sent from my iPhone > > > > > > On Jan 30, 2019, at 5:36 PM, Harsh Patel > wrote: > > > > > >> Hello, > > >> > > >> This mail is to inform you that the integration of DPDK is working > with ns-3 on a basic level. The model is running. > > >> For UDP traffic we are getting throughput same or better than raw > socket. (Around 100Mbps) > > >> But unfortunately for TCP, there are burst packet losses due to whic= h > the throughput is drastically affected after some point of time. The > bandwidth of the link used was 100Mbps. > > >> We have obtained cwnd and ssthresh graphs which show that once the > flow gets out from Slow Start mode, there are so many packet losses that > the congestion window & the slow start threshold is not able to go above > 4-5 packets. > > > > > > Can you determine where the packets are being dropped? > > >> We have attached the graphs with this mail. > > >> > > > > > > I do not see the graphs attached but that=E2=80=99s OK. > > >> We would like to know if there is any reason to this or how can we > fix this. > > > > > > I think we have to find out where the packets are being dropped this > is the only reason for the case to your referring to. > > >> > > >> Thanks & Regards > > >> Harsh & Hrishikesh > > >> > > >> On Wed, 16 Jan 2019 at 19:25, Harsh Patel > wrote: > > >> Hi > > >> > > >> We were able to optimise the DPDK version. There were couple of > things we needed to do. > > >> > > >> We were using tx timeout as 1s/2048, which we found out to be very > less. Then we increased the timeout, but we were getting lot of > retransmissions. > > >> > > >> So we removed the timeout and sent single packet as soon as we get > it. This increased the throughput. > > >> > > >> Then we used DPDK feature to launch function on core, and gave a > dedicated core for Rx. This increased the throughput further. > > >> > > >> The code is working really well for low bandwidth (<~50Mbps) and is > outperforming raw socket version. > > >> But for high bandwidth, we are getting packet length mismatches for > some reason. We are investigating it. > > >> > > >> We really thank you for the suggestions given by you and also for > keeping the patience for last couple of months. > > >> > > >> Thank you > > >> > > >> Regards, > > >> Harsh & Hrishikesh > > >> > > >> On Fri, Jan 4, 2019, 11:27 Harsh Patel > wrote: > > >> Yes that would be helpful. > > >> It'd be ok for now to use the same dpdk version to overcome the buil= d > issues. > > >> We will look into updating the code for latest versions once we get > past this problem. > > >> > > >> Thank you very much. > > >> > > >> Regards, > > >> Harsh & Hrishikesh > > >> > > >> On Fri, Jan 4, 2019, 04:13 Wiles, Keith > wrote: > > >> > > >> > > >> > On Jan 3, 2019, at 12:12 PM, Harsh Patel > wrote: > > >> > > > >> > 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 > > >> > > >> Performance reduced by removing that link status check, that is weir= d. > > >> > > > >> > 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 initializati= on. > > >> > 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 > > >> > > >> I guess you are having vTune start your application and that is why > you have init time items in your log. I normally start my application and > then attach vtune to the application. One of the options in configuration > of vtune for that project is to attach to the application. Maybe it would > help hear. > > >> > > >> Looking at the data you provided it was ok. The problem is it would > not load the source files as I did not have the same build or executable.= I > tried to build the code, but it failed to build and I did not go further.= I > guess I would need to see the full source tree and the executable you use= d > to really look at the problem. I have limited time, but I can try if you > like. > > >> > > > >> > > > >> > Effective CPU Utilization: 21.4% (0.856 out of 4) > > >> > > > >> > Here is the link to vtune profiling results. > https://drive.google.com/open?id=3D1M6g2iRZq2JGPoDVPwZCxWBo7qzUhvWi5 > > >> > > > >> > Thank you > > >> > > > >> > Regards > > >> > > > >> > On Sun, Dec 30, 2018, 06:00 Wiles, Keith > wrote: > > >> > > > >> > > > >> > > On Dec 29, 2018, at 4:03 PM, Harsh Patel < > thadodaharsh10@gmail.com> 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 Effectiv= e > 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 ou= t > 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_sch= ed > inside the rte_mbuf structure. The rte_mbuf_sched was inside the big unio= n > as a hack I moved the struct outside of the rte_mbuf structure and replac= ed > the struct in the union with =E2=80=99struct rte_mbuf_sched sched;', but = I am > guessing you are missing some compiler options in your build system as DP= DK > 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 > > >> > > > >> > > >> Regards, > > >> Keith > > >> > > >> > > >> > > > > Regards, > > Keith > > > > Regards, > Keith > >