Configure out AIO support

This patchs adds the CONFIG_AIO option which allows to remove support
for asynchronous I/O operations, that are not necessarly used by
applications, particularly on embedded devices. As this is a
size-reduction option, it depends on CONFIG_EMBEDDED. It allows to
save ~7 kilobytes of kernel code/data:

   text	   data	    bss	    dec	    hex	filename
1115067	 119180	 217088	1451335	 162547	vmlinux
1108025	 119048	 217088	1444161	 160941	vmlinux.new
  -7042    -132       0   -7174   -1C06 +/-

This patch has been originally written by Matt Mackall
<mpm@selenic.com>, and is part of the Linux Tiny project.

[randy.dunlap@oracle.com: build fix]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Zach Brown <zach.brown@oracle.com>
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/Makefile b/fs/Makefile
index b6f27dc26b72..d0c69f57e5bf 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -8,7 +8,7 @@
 obj-y :=        open.o read_write.o file_table.o super.o \
                 char_dev.o stat.o exec.o pipe.o namei.o fcntl.o \
                 ioctl.o readdir.o select.o fifo.o dcache.o inode.o \
-                attr.o bad_inode.o file.o filesystems.o namespace.o aio.o \
+                attr.o bad_inode.o file.o filesystems.o namespace.o \
                 seq_file.o xattr.o libfs.o fs-writeback.o \
                 pnode.o drop_caches.o splice.o sync.o utimes.o \
                 stack.o
@@ -27,6 +27,7 @@ obj-$(CONFIG_ANON_INODES)	+= anon_inodes.o
 obj-$(CONFIG_SIGNALFD)          += signalfd.o
 obj-$(CONFIG_TIMERFD)           += timerfd.o
 obj-$(CONFIG_EVENTFD)           += eventfd.o
+obj-$(CONFIG_AIO)               += aio.o
 obj-$(CONFIG_FILE_LOCKING)      += locks.o
 obj-$(CONFIG_COMPAT)            += compat.o compat_ioctl.o