suse man page for do_splice_direct

DO_SPLICE_DIRECT(9)						    splice API						       DO_SPLICE_DIRECT(9)

NAME
       do_splice_direct - splices data directly between two files

SYNOPSIS
       long do_splice_direct(struct file * in, loff_t * ppos, struct file * out, size_t len, unsigned int flags);

ARGUMENTS
       in
	   file to splice from

       ppos
	   input file offset

       out
	   file to splice to

       len
	   number of bytes to splice

       flags
	   splice modifier flags

DESCRIPTION
       For use by do_sendfile. splice can easily emulate sendfile, but doing it in the application would incur an extra system call (splice in +
       splice out, as compared to just sendfile). So this helper can splice directly through a process-private pipe.

COPYRIGHT
Kernel Hackers Manual 2.6.					     July 2010						       DO_SPLICE_DIRECT(9)