Forwarding to community. Regards, Ajith
---------- Forwarded message ---------- From: Ajith Adapa <adapa.aj...@gmail.com> Date: Sun, Nov 11, 2012 at 5:14 PM Subject: Re: [E1000-devel] Doubt regarding NIC card performance To: Kyle Creyts <k...@lastline.com> Thanks for the reply kyle. I will try disabling the flow control and check the same. But you are also right if the listening box can't keep up with the rate its of no great use. But next time I will make sure listener is able to keep up with the speed. I have one more doubt Currently we create a SKB before sending pkt to e1000 driver. Is there any way I can directly write into DMA of hardware via driver, resulting direct transmission of pkt instead of doing copy and write operations for every pkt ?? Sorry if I sound naive but I feel even the driver takes a skb and copies its contents to DMA of hardware ?? Thanks, Ajith On Sun, Nov 11, 2012 at 1:38 PM, Kyle Creyts <k...@lastline.com> wrote: > disabling flow control on the listening or sending box seems to sound like > it could solve the problem, though if your listening box can't keep up, what > is the point? > > On Sat, Nov 10, 2012 at 5:51 AM, Ajith Adapa <adapa.aj...@gmail.com> wrote: >> >> Hi, >> >> I have few doubts regarding the performance metrics of e1000 driver. >> >> I am currently using 82546 intel dual port gigabit nic card (ideally >> should be able to generate traffic at line rates) using e1000 driver >> >> # ethtool -i eth1 >> driver: e1000 >> version: 7.3.21-k8-NAPI >> firmware-version: >> bus-info: 0000:0d:00.0 >> supports-statistics: yes >> supports-test: yes >> supports-eeprom-access: yes >> supports-register-dump: yes >> >> I am trying to generate traffic at line rates for packet sizes 1500, >> 1280bytes. But I have observed that I am not even able to make 90% of >> line rate. >> >> I have increased the tx buffer size to 4096 using ethtool but seems of >> not much help. Even disabled pause option for rx and tx which >> initially showed good numbers but later found that stats have some >> strange values. not sure what it means >> >> tx_restart_queue: 6750532 >> >> What I am observing was memory alloted in socket (around 100MB) for >> SKB is filled off after certain time. Is NIC not able to transmit at >> line rate as a result not able to free accordingly ?? >> >> Does the ethernet pause frames makes the NIC card to slow down ?? If >> so disabling it will it transmit the traffic at line rates ? >> >> Can anyone help me how can I tweak NIC card settings to get line rates >> ?? .. I bet there is enough juice in the card to transmit at line >> rates but am I missing anything here ? >> >> Thanks, >> Ajith >> >> >> ------------------------------------------------------------------------------ >> Everyone hates slow websites. So do we. >> Make your web apps faster with AppDynamics >> Download AppDynamics Lite for free today: >> http://p.sf.net/sfu/appdyn_d2d_nov >> _______________________________________________ >> E1000-devel mailing list >> E1000-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/e1000-devel >> To learn more about Intel® Ethernet, visit >> http://communities.intel.com/community/wired > > ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_nov _______________________________________________ E1000-devel mailing list E1000-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired
