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authorThomas Petazzoni <thomas.petazzoni@free-electrons.com>2008-10-15 22:05:12 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-16 11:21:51 -0700
commitebf3f09c634906d371f2bfd71b41c7e0c52efe7e (patch)
tree4205040f47fba2675dc4c6b1407d15c9d6f8b355
parentd8273674721faaf84bec2190c0c7a82972b37f73 (diff)
downloadlinux-sh-ebf3f09c634906d371f2bfd71b41c7e0c52efe7e.tar.gz
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>
-rw-r--r--fs/Makefile3
-rw-r--r--include/linux/aio.h9
-rw-r--r--init/Kconfig8
-rw-r--r--kernel/sys_ni.c5
-rw-r--r--kernel/sysctl.c2
5 files changed, 26 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
diff --git a/include/linux/aio.h b/include/linux/aio.h
index 09b276c35227..f6b8cf99b596 100644
--- a/include/linux/aio.h
+++ b/include/linux/aio.h
@@ -204,12 +204,21 @@ struct kioctx {
/* prototypes */
extern unsigned aio_max_size;
+#ifdef CONFIG_AIO
extern ssize_t wait_on_sync_kiocb(struct kiocb *iocb);
extern int aio_put_req(struct kiocb *iocb);
extern void kick_iocb(struct kiocb *iocb);
extern int aio_complete(struct kiocb *iocb, long res, long res2);
struct mm_struct;
extern void exit_aio(struct mm_struct *mm);
+#else
+static inline ssize_t wait_on_sync_kiocb(struct kiocb *iocb) { return 0; }
+static inline int aio_put_req(struct kiocb *iocb) { return 0; }
+static inline void kick_iocb(struct kiocb *iocb) { }
+static inline int aio_complete(struct kiocb *iocb, long res, long res2) { return 0; }
+struct mm_struct;
+static inline void exit_aio(struct mm_struct *mm) { }
+#endif /* CONFIG_AIO */
#define io_wait_to_kiocb(wait) container_of(wait, struct kiocb, ki_wait)
diff --git a/init/Kconfig b/init/Kconfig
index 8a8e2d00c40e..5ceff3249a2d 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -713,6 +713,14 @@ config SHMEM
option replaces shmem and tmpfs with the much simpler ramfs code,
which may be appropriate on small systems without swap.
+config AIO
+ bool "Enable AIO support" if EMBEDDED
+ default y
+ help
+ This option enables POSIX asynchronous I/O which may by used
+ by some high performance threaded applications. Disabling
+ this option saves about 7k.
+
config VM_EVENT_COUNTERS
default y
bool "Enable VM event counters for /proc/vmstat" if EMBEDDED
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 503d8d4eb80a..a77b27b11b04 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -126,6 +126,11 @@ cond_syscall(sys_vm86);
cond_syscall(compat_sys_ipc);
cond_syscall(compat_sys_sysctl);
cond_syscall(sys_flock);
+cond_syscall(sys_io_setup);
+cond_syscall(sys_io_destroy);
+cond_syscall(sys_io_submit);
+cond_syscall(sys_io_cancel);
+cond_syscall(sys_io_getevents);
/* arch-specific weak syscall entries */
cond_syscall(sys_pciconfig_read);
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 9792c315676a..617d41e4d6a0 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1281,6 +1281,7 @@ static struct ctl_table fs_table[] = {
.extra2 = &two,
},
#endif
+#ifdef CONFIG_AIO
{
.procname = "aio-nr",
.data = &aio_nr,
@@ -1295,6 +1296,7 @@ static struct ctl_table fs_table[] = {
.mode = 0644,
.proc_handler = &proc_doulongvec_minmax,
},
+#endif /* CONFIG_AIO */
#ifdef CONFIG_INOTIFY_USER
{
.ctl_name = FS_INOTIFY,