As find_lock_page() already checks with TestSetPageLocked() that page is
locked, there is no need to call lock_page() that will try-lock page again
(chances of page being unlocked in between are small). Call __lock_page()
directly, this saves one atomic operation.
Also, mark truncate-while-slept path as unlikely while we are here.
(akpm: ug. But this is actually a common path for normal old read()s against
a page which is under readahead I/O so ho-hum.)
Signed-off-by: Nikita Danilov <danilov@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
bbfbb7cec9