Currently, I have no idea to find out memory mapping of virtual machines. I think -n 4 will work on both dual and quad channel memory. This optimizes entries of mempool or ring structure to interleave memory access into n-ways. I think interleaving in 4 ways will also include 2 way interleaving.
Keunhong. 2015-06-29 8:46 GMT+09:00 Abhishek Verma <abhishekv.verma at gmail.com>: > Thanks Keunhong. > > How do i get the motherboard spec on a virtual machine thats spawned on > the cloud, for example Amazon EC2? > > Cheers, Abhishek > > > On Mon, Jun 29, 2015 at 4:53 AM, Keunhong Lee <dlrmsghd at gmail.com> wrote: > >> See your motherboard spec. >> For example, I'm using Intel 5930K with ASUS X99 Delux Motherboard (x99 >> chipset). >> This site https://www.asus.com/us/Motherboards/X99DELUXE/specifications/ >> tells that >> "Quad Channel Memory Architecture " >> which means that "-n 4" is the correct configuration for me. >> >> To fully use quad channel memory, I have to use 4 separated DRAM, >> installed on different memory slots of my motherboard. >> >> -n option optimizes memory bank access pattern for datastructures. >> Since most motherboards support dual or quad memory channel, >> -n 4 will work for most systems. (Only few motherboards support >> tri-channel memory) >> >> I hope that this information is useful to you. >> Keunhong. >> >> >> >> 2015-06-28 18:54 GMT+09:00 Abhishek Verma <abhishekv.verma at gmail.com>: >> >>> Hi, >>> >>> I am new to DPDK and i tried searching the archives in case this had been >>> discussed but couldnt find any references and hence this email: >>> >>> What is the significance of " -n NUM: Number of memory channels per >>> processor socket" which is passed as an EAL option? I have a virtual >>> machine (VM) spawned using VirtualBox and i am trying to use DPDK to get >>> faster access to packets there. I did lscpu, but that didnt give me >>> anything interesting that i could use here: >>> >>> abhishekV at VirtualBox:~/dpdk/dpdk-2.0.0/x86_64-native-linuxapp-gcc/app$ >>> sudo >>> lscpu >>> [sudo] password for abhishekV: >>> >>> Architecture: x86_64 >>> CPU op-mode(s): 32-bit, 64-bit >>> Byte Order: Little Endian >>> CPU(s): 2 >>> On-line CPU(s) list: 0,1 >>> Thread(s) per core: 1 >>> Core(s) per socket: 2 >>> Socket(s): 1 >>> NUMA node(s): 1 >>> Vendor ID: GenuineIntel >>> CPU family: 6 >>> Model: 58 >>> Stepping: 9 >>> CPU MHz: 2594.017 >>> BogoMIPS: 5188.03 >>> L1d cache: 32K >>> L1d cache: 32K >>> L2d cache: 6144K >>> NUMA node0 CPU(s): 0,1 >>> abhishekV at VirtualBox:~/dpdk/dpdk-2.0.0/x86_64-native-linuxapp-gcc/app$ >>> >>> I understand that i have two cores and hence should use -c 1 (since i >>> have >>> cores 0 and 1). However, i dont understand what to give as the "-n" >>> option. >>> Is it always 4? >>> >>> Thanks, Abhishek >>> >> >> >
