feature request: sendfile management

[Andrey N. Oktyabrski]

MZ wrote:
> man sendfile:
>      The flags argument has one possible value: SF_NODISKIO.  This flag
> causes any sendfile() call which would block on disk I/O to instead
> return EBUSY.  Busy servers may benefit by transferring requests that
> would block to a separate I/O worker thread.
> 
> может стоит использовать эту фишку ?
> если EBUSY, то отдавать самому без sendfile, а иначе пусть ядро отдает ?
ano at shrek:~> uname -sr
SunOS 5.10
ano at shrek:~> man sendfile
...
ssize_t sendfile(int out_fd, int in_fd, off_t  *off,  size_t len);
...
Где тут "The flags argument"?