Jens Axboe <axboe@xxxxxxx> wrote:
DVD burning probably isn't a good splice fit, since you need to do
more than actually just point the device at the data. SG_IO is
already zero-copy as it maps the user data into the kernel without
copying, so there's very little room for improvement there to begin
with.
DVD burning on linux is mostly:
mkisofs .... | growisofs ....
Ideally, on mkisofs side, we'd be able to:
- write some data/padding into the pipe
- splice a HUGE file into the pipe
- write some data/padding into the pipe
- splice a HUGE file into the pipe
...
On growisofs side, we'd be able to:
- send some commands
- splice N MBs of data from the pipe to the driver
- send some commands
- splice M MBs of data from the pipe to the driver
...
What'd be nice is an ioctl to change the size of the pipe between
mkisofs and growisofs.