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

[Paul Fulghum]

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

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