tree b08df3f006762cc213543f2ccd1095f2d9afab52
parent 87a6aca504d65f242589583e04df5e74b5eae1fe
author Mel Gorman <mel@csn.ul.ie> 1267568659 +0000
committer Greg Kroah-Hartman <gregkh@suse.de> 1269008273 -0700

tty: Take a 256 byte padding into account when buffering below 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>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>