[PATCH 00/19] lib: Some #include cleanups

[PATCH 00/19] lib: Some #include cleanups

[Rasmus Villemoes]

I'm contemplating doing some tree-wide spring cleaning, mostly
consisting of removing redundant includes, but also refactoring some
large and heterogeneous headers into smaller pieces.

This patch series consists of low-hanging fruit I picked from
lib/. I've verified that "objdump -d lib/builtin.o" produces identical
output for {allyes,allno,def}config, but this is of course only for
x86_64. There's a small but measurable build time improvement: A
defconfig build of lib/ from a clean tree is consistently .5 seconds
(2 %) faster with these patches. There are lots of other apparently
unused headers in lib/*.c, but I've only removed those where it
actually ends up disappearing from the .cmd dependency file (since
that's where the potential build gain lies, and helps prove that the
header is indeed redundant).

I expect there is much larger speedups to gain from removing includes
from .h files, but that is of course at the same time a huge can of
worms, involving boatloads of tree-wide patches updating users to
include what they use directly. So before I start doing that, I'd like
to hear if people think it would be futile.

Rasmus Villemoes (19):
  lib/interval_tree.c: Simplify includes
  lib/sort.c: Use simpler includes
  lib/dynamic_queue_limits.c: Simplify includes
  lib/halfmd4.c: Simplify includes
  lib/idr.c: Remove redundant include
  lib/genalloc.c: Remove redundant include
  lib/list_sort.c: Rearrange includes
  lib/md5.c: Simplify include
  lib/llist.c: Remove redundant include
  lib/kobject_uevent.c: Remove redundant include
  lib/nlattr.c: Remove redundant include
  lib/plist.c: Remove redundant include
  lib/radix-tree.c: Change to simpler include
  lib/show_mem.c: Remove redundant include
  lib/sort.c: Move include inside #if 0
  lib/stmp_device.c: Replace module.h include
  lib/strncpy_from_user.c: Replace module.h include
  lib/percpu_ida.c: Remove redundant includes
  lib/lcm.c: Replace include

 include/linux/cryptohash.h | 2 ++
 lib/dynamic_queue_limits.c | 4 ++--
 lib/genalloc.c             | 1 -
 lib/halfmd4.c              | 2 +-
 lib/idr.c                  | 1 -
 lib/interval_tree.c        | 4 ++--
 lib/kobject_uevent.c       | 1 -
 lib/lcm.c                  | 2 +-
 lib/list_sort.c            | 7 +++++--
 lib/llist.c                | 1 -
 lib/md5.c                  | 2 +-
 lib/nlattr.c               | 1 -
 lib/percpu_ida.c           | 3 ---
 lib/plist.c                | 1 -
 lib/radix-tree.c           | 2 +-
 lib/show_mem.c             | 1 -
 lib/sort.c                 | 6 +++---
 lib/stmp_device.c          | 3 ++-
 lib/strncpy_from_user.c    | 3 ++-
 19 files changed, 22 insertions(+), 25 deletions(-)

-- 
2.1.3

[PATCH 01/19] lib/interval_tree.c: Simplify includes

[Rasmus Villemoes]

The file uses nothing from init.h, and also doesn't need the full
module.h machinery; export.h is sufficient. The latter requires the
user to ensure compiler.h is included, so do that explicitly instead
of relying on some other header pulling it in.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/interval_tree.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/interval_tree.c b/lib/interval_tree.c
index f367f9ad544c..c85f6600a5f8 100644
--- a/lib/interval_tree.c
+++ b/lib/interval_tree.c
@@ -1,7 +1,7 @@
-#include <linux/init.h>
 #include <linux/interval_tree.h>
 #include <linux/interval_tree_generic.h>
-#include <linux/module.h>
+#include <linux/compiler.h>
+#include <linux/export.h>
 
 #define START(node) ((node)->start)
 #define LAST(node)  ((node)->last)
-- 
2.1.3

[PATCH 02/19] lib/sort.c: Use simpler includes

[Rasmus Villemoes]

sort.c doesn't use facilities from kernel.h, but does use some types
defined in linux/types.h. Include the latter directly instead of
relying on some other header doing it. Similarly, include
linux/export.h directly instead of through module.h. This removes 80
lines from the dependency file .sort.o.cmd.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/sort.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/sort.c b/lib/sort.c
index 926d00429ed2..14fc1dfadb3f 100644
--- a/lib/sort.c
+++ b/lib/sort.c
@@ -4,8 +4,8 @@
  * Jan 23 2005  Matt Mackall <mpm@selenic.com>
  */
 
-#include <linux/kernel.h>
-#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/export.h>
 #include <linux/sort.h>
 #include <linux/slab.h>
 
-- 
2.1.3

[PATCH 03/19] lib/dynamic_queue_limits.c: Simplify includes

[Rasmus Villemoes]

The file doesn't use anything from ctype.h. Instead of module.h, just
use export.h for EXPORT_SYMBOL. The latter requires the user to
include compiler.h, so do that explicitly instead of relying on some
other header pulling it in.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/dynamic_queue_limits.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/dynamic_queue_limits.c b/lib/dynamic_queue_limits.c
index 0777c5a45fa0..f346715e2255 100644
--- a/lib/dynamic_queue_limits.c
+++ b/lib/dynamic_queue_limits.c
@@ -3,12 +3,12 @@
  *
  * Copyright (c) 2011, Tom Herbert <therbert@google.com>
  */
-#include <linux/module.h>
 #include <linux/types.h>
-#include <linux/ctype.h>
 #include <linux/kernel.h>
 #include <linux/jiffies.h>
 #include <linux/dynamic_queue_limits.h>
+#include <linux/compiler.h>
+#include <linux/export.h>
 
 #define POSDIFF(A, B) ((int)((A) - (B)) > 0 ? (A) - (B) : 0)
 #define AFTER_EQ(A, B) ((int)((A) - (B)) >= 0)
-- 
2.1.3

[PATCH 04/19] lib/halfmd4.c: Simplify includes

[Rasmus Villemoes]

We only need EXPORT_SYMBOL, so compiler.h and export.h suffice. This
means linux/types.h is no longer implicitly included, so add an
include of uapi/linux/types.h to linux/cryptohash.h for __u32. Other
users of cryptohash.h cannot be affected, since they must already have
been including uapi/linux/types.h in order for gcc not to complain
about unknown types.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 include/linux/cryptohash.h | 2 ++
 lib/halfmd4.c              | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/linux/cryptohash.h b/include/linux/cryptohash.h
index 2cd9f1cf9fa3..f4754282c9c2 100644
--- a/include/linux/cryptohash.h
+++ b/include/linux/cryptohash.h
@@ -1,6 +1,8 @@
 #ifndef __CRYPTOHASH_H
 #define __CRYPTOHASH_H
 
+#include <uapi/linux/types.h>
+
 #define SHA_DIGEST_WORDS 5
 #define SHA_MESSAGE_BYTES (512 /*bits*/ / 8)
 #define SHA_WORKSPACE_WORDS 16
diff --git a/lib/halfmd4.c b/lib/halfmd4.c
index 66d0ee8b7776..a8fe6274a13c 100644
--- a/lib/halfmd4.c
+++ b/lib/halfmd4.c
@@ -1,4 +1,4 @@
-#include <linux/kernel.h>
+#include <linux/compiler.h>
 #include <linux/export.h>
 #include <linux/cryptohash.h>
 
-- 
2.1.3

[PATCH 05/19] lib/idr.c: Remove redundant include

[Rasmus Villemoes]

idr.c doesn't seem to use anything from hardirq.h (or anything
included from that). Removing it produces identical objdump -d output,
and gives 44 fewer lines in the .idr.o.cmd dependency file.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/idr.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lib/idr.c b/lib/idr.c
index e654aebd5f80..5335c43adf46 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -30,7 +30,6 @@
 #include <linux/idr.h>
 #include <linux/spinlock.h>
 #include <linux/percpu.h>
-#include <linux/hardirq.h>
 
 #define MAX_IDR_SHIFT		(sizeof(int) * 8 - 1)
 #define MAX_IDR_BIT		(1U << MAX_IDR_SHIFT)
-- 
2.1.3

[PATCH 06/19] lib/genalloc.c: Remove redundant include

[Rasmus Villemoes]

Removing this include produces byte-identical output, and thus removes
a false dependency.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/genalloc.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lib/genalloc.c b/lib/genalloc.c
index 2e65d206b01c..17d8f58f6716 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -34,7 +34,6 @@
 #include <linux/rculist.h>
 #include <linux/interrupt.h>
 #include <linux/genalloc.h>
-#include <linux/of_address.h>
 #include <linux/of_device.h>
 
 static inline size_t chunk_size(const struct gen_pool_chunk *chunk)
-- 
2.1.3

[PATCH 07/19] lib/list_sort.c: Rearrange includes

[Rasmus Villemoes]

Memory allocation only happens in the self test, just as random
numbers are only used there. So move the inclusion of slab.h inside
the CONFIG_TEST_LIST_SORT.

We don't need module.h and all of the stuff it carries with it, so
replace with export.h and compiler.h. Unfortunately, the ARRAY_SIZE
macro from kernel.h requires the user to ensure bug.h is also included
(for BUILD_BUG_ON_ZERO, used by __must_be_array). We used to get that
through some maze of nested includes, but just include it explicitly.

linux/string.h is then only included implicitly through
kernel.h->printk.h->dynamic_debug.h, but only if
!CONFIG_DYNAMIC_DEBUG, so just include it explicitly (for memset).

objdump -d says the generated code is the same, and wc -l says that
lib/.list_sort.o.cmd went from 579 to 165 lines.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/list_sort.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/lib/list_sort.c b/lib/list_sort.c
index 12bcba1c8612..b29015102698 100644
--- a/lib/list_sort.c
+++ b/lib/list_sort.c
@@ -2,9 +2,11 @@
 #define pr_fmt(fmt) "list_sort_test: " fmt
 
 #include <linux/kernel.h>
-#include <linux/module.h>
+#include <linux/bug.h>
+#include <linux/compiler.h>
+#include <linux/export.h>
+#include <linux/string.h>
 #include <linux/list_sort.h>
-#include <linux/slab.h>
 #include <linux/list.h>
 
 #define MAX_LIST_LENGTH_BITS 20
@@ -146,6 +148,7 @@ EXPORT_SYMBOL(list_sort);
 
 #ifdef CONFIG_TEST_LIST_SORT
 
+#include <linux/slab.h>
 #include <linux/random.h>
 
 /*
-- 
2.1.3

[PATCH 08/19] lib/md5.c: Simplify include

[Rasmus Villemoes]

md5.c doesn't use anything from kernel.h, except that that pulls in
compiler.h, which is needed for the export.h to work.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/md5.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/md5.c b/lib/md5.c
index 958a3c15923c..bb0cd01d356d 100644
--- a/lib/md5.c
+++ b/lib/md5.c
@@ -1,4 +1,4 @@
-#include <linux/kernel.h>
+#include <linux/compiler.h>
 #include <linux/export.h>
 #include <linux/cryptohash.h>
 
-- 
2.1.3

[PATCH 09/19] lib/llist.c: Remove redundant include

[Rasmus Villemoes]

This file doesn't seem to use anything provided by linux/interrupt.h
or anything recursively included through that. Removing it produces
byte-identical output, while reducing .llist.o.cmd from 541 to 156
lines.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/llist.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lib/llist.c b/lib/llist.c
index f76196d07409..0b0e9779d675 100644
--- a/lib/llist.c
+++ b/lib/llist.c
@@ -24,7 +24,6 @@
  */
 #include <linux/kernel.h>
 #include <linux/export.h>
-#include <linux/interrupt.h>
 #include <linux/llist.h>
 
 
-- 
2.1.3

[PATCH 10/19] lib/kobject_uevent.c: Remove redundant include

[Rasmus Villemoes]

The file doesn't seem to use anything from linux/user_namespace.h, and
removing it yields byte-identical object code and strictly fewer
dependencies in the .cmd file.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/kobject_uevent.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 9ebf9e20de53..f6c2c1e7779c 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -20,7 +20,6 @@
 #include <linux/export.h>
 #include <linux/kmod.h>
 #include <linux/slab.h>
-#include <linux/user_namespace.h>
 #include <linux/socket.h>
 #include <linux/skbuff.h>
 #include <linux/netlink.h>
-- 
2.1.3

[PATCH 11/19] lib/nlattr.c: Remove redundant include

[Rasmus Villemoes]

nlattr.c doesn't seem to rely on anything from netdevice.h. Removing
it yields identical objdump -d output for each of {allyes,allno,def}config,
and eliminates more than 200 lines from the generated dependency file.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/nlattr.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lib/nlattr.c b/lib/nlattr.c
index 9c3e85ff0a6c..76a1b59523ab 100644
--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -9,7 +9,6 @@
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/jiffies.h>
-#include <linux/netdevice.h>
 #include <linux/skbuff.h>
 #include <linux/string.h>
 #include <linux/types.h>
-- 
2.1.3

[PATCH 12/19] lib/plist.c: Remove redundant include

[Rasmus Villemoes]

Removing the include of linux/spinlock.h produces byte-identical
output for {allno,def}config, and identical objdump -d output for
allyesconfig. In the former two cases, more than a 100 lines are
eliminated from the generated dependency file.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/plist.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lib/plist.c b/lib/plist.c
index d408e774b746..3a30c53db061 100644
--- a/lib/plist.c
+++ b/lib/plist.c
@@ -25,7 +25,6 @@
 
 #include <linux/bug.h>
 #include <linux/plist.h>
-#include <linux/spinlock.h>
 
 #ifdef CONFIG_DEBUG_PI_LIST
 
-- 
2.1.3

[PATCH 13/19] lib/radix-tree.c: Change to simpler include

[Rasmus Villemoes]

The comment helpfully explains why hardirq.h is included, but since
2d4b84739f0a ("hardirq: Split preempt count mask definitions")
in_interrupt() has been provided by preempt_mask.h. Use that instead,
saving around 40 lines in the generated dependency file.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/radix-tree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 3291a8e37490..3d2aa27b845b 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -33,7 +33,7 @@
 #include <linux/string.h>
 #include <linux/bitops.h>
 #include <linux/rcupdate.h>
-#include <linux/hardirq.h>		/* in_interrupt() */
+#include <linux/preempt_mask.h>		/* in_interrupt() */
 
 
 /*
-- 
2.1.3

[PATCH 14/19] lib/show_mem.c: Remove redundant include

[Rasmus Villemoes]

show_mem.c doesn't use anything from nmi.h. Removing it yields
identical objdump -d output for each of {allyes,allno,def}config and
eliminates more than 100 lines in the dependency file.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/show_mem.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lib/show_mem.c b/lib/show_mem.c
index 7de89f4a36cf..adc98e1825ba 100644
--- a/lib/show_mem.c
+++ b/lib/show_mem.c
@@ -6,7 +6,6 @@
  */
 
 #include <linux/mm.h>
-#include <linux/nmi.h>
 #include <linux/quicklist.h>
 #include <linux/cma.h>
 
-- 
2.1.3

[PATCH 15/19] lib/sort.c: Move include inside #if 0

[Rasmus Villemoes]

The sort function and its helpers don't do memory allocation, so the
slab.h include is redundant. Move it inside the #if 0 protecting the
self-test, similar to how it is done in lib/list_sort.c. This removes
over 450 lines from the generated dependency file.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/sort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/sort.c b/lib/sort.c
index 14fc1dfadb3f..43c9fe73ae2e 100644
--- a/lib/sort.c
+++ b/lib/sort.c
@@ -7,7 +7,6 @@
 #include <linux/types.h>
 #include <linux/export.h>
 #include <linux/sort.h>
-#include <linux/slab.h>
 
 static void u32_swap(void *a, void *b, int size)
 {
@@ -85,6 +84,7 @@ void sort(void *base, size_t num, size_t size,
 EXPORT_SYMBOL(sort);
 
 #if 0
+#include <linux/slab.h>
 /* a simple boot-time regression test */
 
 int cmpint(const void *a, const void *b)
-- 
2.1.3

[PATCH 16/19] lib/stmp_device.c: Replace module.h include

[Rasmus Villemoes]

stmp_device.c only needs EXPORT_SYMBOL, so just include compiler.h and
export.h instead of the whole module.h machinery.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/stmp_device.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/stmp_device.c b/lib/stmp_device.c
index 8ac9bcc4289a..a904656f4fd7 100644
--- a/lib/stmp_device.c
+++ b/lib/stmp_device.c
@@ -15,7 +15,8 @@
 #include <linux/io.h>
 #include <linux/errno.h>
 #include <linux/delay.h>
-#include <linux/module.h>
+#include <linux/compiler.h>
+#include <linux/export.h>
 #include <linux/stmp_device.h>
 
 #define STMP_MODULE_CLKGATE	(1 << 30)
-- 
2.1.3

[PATCH 17/19] lib/strncpy_from_user.c: Replace module.h include

[Rasmus Villemoes]

strncpy_from_user.c only needs EXPORT_SYMBOL, so just include
compiler.h and export.h instead of the whole module.h machinery.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/strncpy_from_user.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c
index bb2b201d6ad0..e0af6ff73d14 100644
--- a/lib/strncpy_from_user.c
+++ b/lib/strncpy_from_user.c
@@ -1,4 +1,5 @@
-#include <linux/module.h>
+#include <linux/compiler.h>
+#include <linux/export.h>
 #include <linux/uaccess.h>
 #include <linux/kernel.h>
 #include <linux/errno.h>
-- 
2.1.3

[PATCH 18/19] lib/percpu_ida.c: Remove redundant includes

[Rasmus Villemoes]

These three #includes seem to be completely redundant: Removing them
yields identical objdump -d output for each of
{allyes,allno,def}config, and neither included file end up in the
generated dependency file through some recursive include. In total,
about 50 lines are eliminated from .percpu.o.cmd.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/percpu_ida.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/lib/percpu_ida.c b/lib/percpu_ida.c
index 93d145e5539c..f75715131f20 100644
--- a/lib/percpu_ida.c
+++ b/lib/percpu_ida.c
@@ -19,13 +19,10 @@
 #include <linux/bug.h>
 #include <linux/err.h>
 #include <linux/export.h>
-#include <linux/hardirq.h>
-#include <linux/idr.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/percpu.h>
 #include <linux/sched.h>
-#include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/spinlock.h>
 #include <linux/percpu_ida.h>
-- 
2.1.3

[PATCH 19/19] lib/lcm.c: Replace include

[Rasmus Villemoes]

We don't need all the stuff kernel.h pulls in; just compiler.h since
export.h doesn't do necessary #includes. This removes more than 100
dependencies.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 lib/lcm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/lcm.c b/lib/lcm.c
index 51cc6b13cd52..e97dbd51e756 100644
--- a/lib/lcm.c
+++ b/lib/lcm.c
@@ -1,4 +1,4 @@
-#include <linux/kernel.h>
+#include <linux/compiler.h>
 #include <linux/gcd.h>
 #include <linux/export.h>
 #include <linux/lcm.h>
-- 
2.1.3