tty: Keep the default buffering to sub-page units
authorAlan Cox <alan@linux.intel.com>
Thu, 18 Feb 2010 16:43:47 +0000 (16:43 +0000)
committerGreg Kroah-Hartman <gregkh@suse.de>
Tue, 2 Mar 2010 22:43:23 +0000 (14:43 -0800)
commitd9661adfb8e53a7647360140af3b92284cbe52d4
tree92946118969a8cbd5918ac6b35142f0051aabc4e
parent4165fe4ef7305609a96c7f248cefb9c414d0ede5
tty: Keep the default buffering to sub-page units

We allocate during interrupts so while our buffering is normally diced up
small anyway on some hardware at speed we can pressure the VM excessively
for page pairs. We don't really need big buffers to be linear so don't try
so hard.

In order to make this work well we will tidy up excess callers to request_room,
which cannot itself enforce this break up.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/char/tty_buffer.c
include/linux/tty.h