tree 03175cd2ce9dd8013c4aaa8e2dd426767aa1a4c7
parent 7391ee16950e772076d321792d9fbf030f921345
author Peter Hurley <peter@hurleysoftware.com> 1371303368 -0400
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1374623228 -0700

tty: Track flip buffer memory limit atomically

Lockless flip buffers require atomically updating the bytes-in-use
watermark.

The pty driver also peeks at the watermark value to limit
memory consumption to a much lower value than the default; query
the watermark with new fn, tty_buffer_space_avail().

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>