Hi Linus, Linus Torvalds wrote: > +static long do_splice_from(struct inode *pipe, struct file *out, size_t len, > unsigned long flags) > +static long do_splice_to(struct file *in, struct inode *pipe, size_t len, > unsigned long flags) > +static long do_splice(struct file *in, struct file *out, size_t len, > unsigned long flags) > +asmlinkage long sys_splice(int fdin, int fdout, size_t len, unsigned long > flags)
That part looks quite perfect. As long as they stay like this, I'm totally happy. I have even no problem about limiting to a length, since I can use that to measure progress (e.g. a simple progress bar). This way I also keep the process as an "actor" like "[EMAIL PROTECTED]" pointed out. It has unnecessary scheduling overhead, but the ability to stop/resume the transfer by killing the process doing it is worth it, I agree. So I would put a structure in the inode identifying the special device and check, whether the "in" and "out" parameters are from devices suitable for a direct on wire transfer. If they are, I just set up some registers and wait for the transfer to happen. Then I get an interrupt/wakeup, if the requested amount is streamed, increment some user space pointers, switch to user space, user space tells me abort or stream more and I follow. Continue until abort by user or streaming problems happen. Just to give you an idea: I debugged such a machine and I had a hard hanging kernel with interrupts disabled. It still got data from a tuner, through an MPEG decoder, an MPEG demultiplexer and played it to the audio card. Not just a buffer like ALSA/OSS, but as long as I would like and it's end to end without any CPU intervention. That behavior would be perfect, but I could also live with a "pushing process". Regards Ingo Oeser - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
