Hi~ Bob, Thanks for your response! So, you think it is memory usage problem rather than QPI issue? That means if I improve the memory usage issue, may the preformance will raise to my expected?
BTW, Have anyone every use DPDK in NUMA and use crossing CPU like my case? If yes, could you tell me how to solve the question? If no, I would to know the DPDK allow user to this kinds of case in their app or not? If the answer is true, I need change a way to use DPDK. above, it has lots of questions. I hope someone can help me to answer the questions. On 09/04/2013 12:19 AM, Bob Chen wrote: QPI bandwidth is definitely large enough, but it seems that QPI is only responsible for the communication between separate CPU chips. What you need to do is actually accessing the memory on the other part, probably not even hit the bandwidth. The latency can be caused by a lot of facts during a NUMA operation. /Bob ------------------ ??? ? ------------------ ???: "Zachary";<zachary.jen at cas-well.com><mailto:zachary.jen at cas-well.com>; ????: 2013?9?2?(???) ??11:22 ???: "dev"<dev at dpdk.org><mailto:dev at dpdk.org>; ??: " "Yannic.Chou (???) : 6808" <yannic.chou at cas-well.com><mailto:yannic.chou at cas-well.com>; "Alan Yu ??? : 6632""<Alan.Yu at cas-well.com><mailto:Alan.Yu at cas-well.com>; ??: [dpdk-dev] DPDK & QPI performance issue in Romley platform. Hi~ I have a question about DPDK & QPI performance issue in Romley platform. Recently, I use DPDK example, l2fwd, to test DPDK's performance in my Romley platform. When I try to do the test, crossing used CPU, I find the performance dramatically decrease. Is it true? Or any method can prove the phenomenon? In my opinion, there should be no this kind of issue here due to QPI have enough bandwidth to deal the kinds of case. Thus, I am so amaze in our results and can not explain it. Could someone can help me to solve this problem. Thank a lot! My testing environment describe as below: Platform: Romley CPU: E5-2643 * 2 RAM: Transcend 8GB PC3-1600 DDR3 * 8 OS: Fedora core 14 DPDK: v1.3.1r2, example/l2fwd Slot setting: SlotA is controled by CPU1 directly. SlotB is controled by CPU0 directly. DPDK pre-setting: a. BIOS setting: HT=disable b. Kernel paramaters isolcpus=2,3,6,7 default_hugepagesz=1024M hugepagesz=1024M hugepages=16 c. OS setting: service avahi-daemon stop service NetworkManager stop service iptables stop service acpid stop selinux disable Example program Command: a. SlotB(CPU0) -> CPU1 #>./l2fwd -c 0xc -n 4 -- -q 1 -p 0xc b. SlotA(CPU1) -> CPU0 #>./l2fwd -c 0xc0 -n 4 -- -q 1 -p 0xc0 Results: use frame size 128 bytes CPU Affinity Slot A (CPU1) Slot B (CPU0) CPU0 15.9% 96.49% CPU1 90.88% 24.78% ????????????????????????????????????????????? This email may contain confidential information. Please do not use or disclose it in any way and delete it if you are not the intended recipient. -- Best Regards, Zachary Jen Software RD CAS-WELL Inc. 8th Floor, No. 242, Bo-Ai St., Shu-Lin City, Taipei County 238, Taiwan Tel: +886-2-7731-8888#6305 Fax: +886-2-7731-9988 ????????????????????????????????????????????? This email may contain confidential information. Please do not use or disclose it in any way and delete it if you are not the intended recipient.
