SPEED
上传用户:ig0539
上传日期:2022-05-21
资源大小:181k
文件大小:1k
- - See also BENCHMARKS
- This FTPd should be very performant. The reasons for this are below, followed
- by specific benchmarks as and when I get them.
- 1) Generally, it is a fairly minimal FTPd. There should not be much code and/or
- syscall bloat.
- 2) For binary downloads, Linux sendfile() is used. This is a lot lighter on
- CPU/syscall usage than your regular read()/write() loop.
- 3) The "ls" command is fully internal. That is to say, an external "ls" command
- does not need to be launch. Launching an external process is costly because
- of the fork(), exec(), ELF loader startup, etc.
- It is not all good news, of course. Potential sources of poor performance
- include
- 1) Overhead of two processes per session (in some common configurations).
- 2) Excessive heap usage hidden behind the string API.
- BENCHMARKS
- ==========
- 1) vsftpd downloads ASCII data at at least twice the rate of wu-ftpd.
- 2) vsftpd has achieved 86Mbyte/sec download over Gigabit ethernet between
- Linux-2.4.x boxes (thanks to sendfile())
- 3) vsftpd has smaller virtual memory usage (and RSS, it seems)
- 4) Various reports have trickled in and indicate that vsftpd thumps wu-ftpd
- in performance tests.