Ivan Korotkov wrote: > this is an enhancement proposal to use sendfile instead of read/write loop > in cp(1) on Linux 2.6.33 and above to speed up copying. WDYT?
The feature is very new. It think it is too new to use in a coreutils command like cp. For anyone who uses a single binary on multiple different kernels (not that uncommon) this could cause the program to use the new sendfile(2) api on the older kernel which does not support it causing pain to those users. In order to use it the program would need to dynamically determine at runtime if the feature was available and only use it then. That adds too much complexity for a simple program like cp should be. Do you have any benchmarks which would show what type of performance improvement can be expected of a change from read(2)-write(2) to sendfile(2) between descriptors? Benchmark data would be most useful in determining the worth of such feature changes. Bob
