On Sun, Apr 17, 2005 at 11:35:23PM +0200, Andrei Badea wrote: > I experience quite high CPU usage during file transfers with lftp at high > transfer rates (around 10 MB/s). Using vmstat I observe about 25% of CPU time > spent in userspace during a get transfer, and 30 to 40% during a mirror > transfer. For comparison, the ftp and wget programs only take something > around 7 > or 8% of userspace CPU time during a file retrieve operation.
I think many of that time os spent on rate calculation, cooperative multithreading, etc. ftp and wget are simpler programs, they have a simple read-write loop for downloading. Profile lftp, find a hot spot and optimize, if cpu usage is critical for you. I did that some time ago and optimized lftp a bit. -- Alexander.
