Re: [Bug #14388] keyboard under X with 2.6.31

Paul Fulghum
2009-10-13T15:33:00Z

On Tue, 2009-10-13 at 07:39 -0700, Linus Torvalds wrote:
> It's not a f*cking performance tweak, and you're ludicrous to claim it is.
> It's pointless, and it's making the code _slower_ rather than faster.
>
> Lookie here, Alan - the common sequence is crap like this:
>
> tty_buffer_request_room(tty, buf->size);
> tty_insert_flip_string(tty, buf->base, buf->size);

The performance tweak of tty_prepare_xxx is that you fill
the tty_buffer directly instead of writing data first to a staging
buffer and then calling tty_insert_flip_string, which just copies
from the staging buffer to the tty_buffer. So it saves a copy operation.

--
Paul Fulghum
Microgate Systems, Ltd