On Wed, Mar 25, 2015 at 10:06:48PM +0800, Cheng Kevin wrote: > Hi all, > > I am a beginner of DPDK. Recently, i am interest in DPDK vHost app - > testpmd. > > And i have been tracing on testpmd.c and iofwd.c for a while. > > Also add some code inside iofwd.c for storing the payload of packets. > > Everything goes fine, and the performance is great as expected. > > But when i use fwrite to store the payload into a file, > > the performance decrease from 800mbps to 3mbps (input stream is 1 Gbps). > > Is is caused by the limitation of Virtual Disk IO? How can i solve it? > > I have tried to search the answer, some people say "pthread" might solve > the problem. > > Can someone give me some hint, i really appreciate for your help. > > > Best Regard, > > Kevin Cheng
Two general issues you will hit writing to disk: 1) IO, including disk IO, is slow 2) System calls are slow. You are probably hitting both bottlenecks. /Bruce
