very low performance tcp/rsh

[Eugene Grosbein]

30.04.2019 2:22, Wojciech Puchar wrote:

> create 32GB hole-file
> 
> dd if=/dev/zero of=test bs=32k seek=1m count=0
> 
> fetch -o /dev/null over ftp (proftpd) gives 1.4GB/s
> 
> proftpd consumed 100% of single core. much better.
> 
> tested with FreeBSD ftpd  - 1.7GB/s
> 
> seems like freebsd can saturate 10Gb/s ethernet with single core (Intel(R) Xeon(R) CPU E5-2620 v4 @ 2.10GHz)
> 
> 
> Still where is the most overhead? one memcopy to packet buffers+creating packet headers (send).
> 
> reception is on separate process taking another core.
> 
> 
> still - quite good. But compared to filesystem overhead - large.

Do not use file with holes (holes require special processing taking lots of CPU cycles).
Create ordinary file within RAM disk and use sock ftp daemon for sake of sendfile().