Re: [PATCH] tty: Take a 256 byte padding into account when buffering below sub-page units

[Greg KH <gregkh@suse.de>]

On Tue, Mar 02, 2010 at 10:24:19PM +0000, Mel Gorman wrote:
> (applies on top of linux-next, depends on "tty: Keep the default buffering to sub-page units")
> 
> The TTY layer takes some care to ensure that only sub-page allocations
> are made with interrupts disabled. It does this by setting a goal of
> "TTY_BUFFER_PAGE" to allocate. Unfortunately, while TTY_BUFFER_PAGE takes the
> size of tty_buffer into account, it fails to account that tty_buffer_find()
> rounds the buffer size out to the next 256 byte boundary before adding on
> the size of the tty_buffer.
> 
> This patch adjusts the TTY_BUFFER_PAGE calculation to take into account the
> size of the tty_buffer and the padding. Once applied, tty_buffer_alloc()
> should not require high-order allocations.
> 
> Signed-off-by: Mel Gorman <mel@csn.ul.ie>
> --- 
>  include/linux/tty.h |    9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)

Thanks, I'll queue this up after the current round of patches make it
into Linus's tree.

greg k-h