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Alexey Dobriyan c7d03a00b5 netns: make struct pernet_operations::id unsigned int 
Make struct pernet_operations::id unsigned.

There are 2 reasons to do so:

1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.

2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.

"int" being used as an array index needs to be sign-extended
to 64-bit before being used.

	void f(long *p, int i)
	{
		g(p[i]);
	}

  roughly translates to

	movsx	rsi, esi
	mov	rdi, [rsi+...]
	call 	g

MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.

Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:

	static inline void *net_generic(const struct net *net, int id)
	{
		...
		ptr = ng->ptr[id - 1];
		...
	}

And this function is used a lot, so those sign extensions add up.

Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)

Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]

However, overall balance is in negative direction:

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
	function                                     old     new   delta
	nfsd4_lock                                  3886    3959     +73
	tipc_link_build_proto_msg                   1096    1140     +44
	mac80211_hwsim_new_radio                    2776    2808     +32
	tipc_mon_rcv                                1032    1058     +26
	svcauth_gss_legacy_init                     1413    1429     +16
	tipc_bcbase_select_primary                   379     392     +13
	nfsd4_exchange_id                           1247    1260     +13
	nfsd4_setclientid_confirm                    782     793     +11
		...
	put_client_renew_locked                      494     480     -14
	ip_set_sockfn_get                            730     716     -14
	geneve_sock_add                              829     813     -16
	nfsd4_sequence_done                          721     703     -18
	nlmclnt_lookup_host                          708     686     -22
	nfsd4_lockt                                 1085    1063     -22
	nfs_get_client                              1077    1050     -27
	tcf_bpf_init                                1106    1076     -30
	nfsd4_encode_fattr                          5997    5930     -67
	Total: Before=154856051, After=154854321, chg -0.00%

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-18 10:59:15 -05:00
..
9p Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
adfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
affs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
afs afs: call->operation_ID sometimes used as __be32 sometimes as u32 2016-10-13 17:03:52 +01:00
autofs4 autofs: refactor ioctl fn vector in iookup_dev_ioctl() 2016-10-11 15:06:31 -07:00
befs befs fixes for 4.9-rc1 2016-10-15 12:09:13 -07:00
bfs Merge remote-tracking branch 'ovl/rename2' into for-linus 2016-10-10 23:02:51 -04:00
btrfs Merge branch 'for-4.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux 2016-11-04 20:08:16 -07:00
cachefiles Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
ceph ceph: use default file splice read callback 2016-11-10 20:13:04 +01:00
cifs CIFS: Retrieve uid and gid from special sid if enabled 2016-10-14 14:22:16 -05:00
coda Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
configfs Merge remote-tracking branch 'ovl/rename2' into for-linus 2016-10-10 23:02:51 -04:00
cramfs
crypto fscrypto: lock inode while setting encryption policy 2016-10-15 09:48:50 -04:00
debugfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
devpts Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
dlm genetlink: mark families as __ro_after_init 2016-10-27 16:16:09 -04:00
ecryptfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
efivarfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
efs
exofs fs: exofs: print a hex number after a 0x prefix 2016-10-27 18:43:43 -07:00
exportfs exportfs: be careful to only return expected errors. 2016-10-06 09:07:44 -04:00
ext2 ext2: avoid bogus -Wmaybe-uninitialized warning 2016-10-18 11:29:35 +02:00
ext4 ext4: add missing KERN_CONT to a few more debugging uses 2016-10-15 09:57:31 -04:00
f2fs This includes fixing a bug which references a wrong pointer, sum_page, in 2016-10-18 14:15:23 -07:00
fat Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
freevxfs
fscache
fuse Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
gfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
hfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
hfsplus Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
hostfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
hpfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
hugetlbfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
isofs isofs: Do not return EACCES for unknown filesystems 2016-10-18 11:28:21 +02:00
jbd2 jbd2: fix incorrect unlock on j_list_lock 2016-10-12 23:19:18 -04:00
jffs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
jfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
kernfs kernfs: Add noop_fsync to supported kernfs_file_fops 2016-10-27 17:47:11 +02:00
lockd netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
logfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
minix Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
ncpfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
nfs netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
nfs_common netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
nfsd netns: make struct pernet_operations::id unsigned int 2016-11-18 10:59:15 -05:00
nilfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
nls
notify fsnotify: clean up spinlock assertions 2016-10-07 18:46:26 -07:00
ntfs fs: remove the never implemented aio_fsync file operation 2016-10-30 13:09:42 -04:00
ocfs2 ocfs2: fix not enough credit panic 2016-11-11 08:12:37 -08:00
omfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
openpromfs fs: Replace CURRENT_TIME with current_time() for inode timestamps 2016-09-27 21:06:21 -04:00
orangefs orangefs: clean up debugfs 2016-11-07 10:41:55 -05:00
overlayfs ovl: fsync after copy-up 2016-10-31 14:42:14 +01:00
proc proc: fix NULL dereference when reading /proc/<pid>/auxv 2016-10-27 18:43:43 -07:00
pstore Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
qnx4
qnx6
quota genetlink: mark families as __ro_after_init 2016-10-27 16:16:09 -04:00
ramfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
reiserfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
romfs
squashfs vfs: Remove {get,set,remove}xattr inode operations 2016-10-07 21:48:36 -04:00
sysfs Merge branch 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2016-10-14 12:18:50 -07:00
sysv Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
tracefs fs: Replace CURRENT_TIME with current_time() for inode timestamps 2016-09-27 21:06:21 -04:00
ubifs ubifs: Fix regression in ubifs_readdir() 2016-10-28 14:48:31 +02:00
udf Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
ufs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
xfs xfs: defer should abort intent items if the trans roll fails 2016-10-24 14:21:18 +11:00
aio.c aio: fix freeze protection of aio writes 2016-10-30 13:09:42 -04:00
anon_inodes.c
attr.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
bad_inode.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c x86/coredump: Use pr_reg size, rather that TIF_IA32 flag 2016-09-14 21:28:10 +02:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c fs: Replace current_fs_time() with current_time() 2016-09-27 21:06:22 -04:00
binfmt_script.c
block_dev.c block: implement (some of) fallocate for block devices 2016-10-11 15:06:30 -07:00
buffer.c fs: use mapping_set_error instead of opencoded set_bit 2016-10-11 15:06:33 -07:00
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c fs: compat_ioctl: add pretimeout functions for watchdogs 2016-09-24 09:27:18 +02:00
compat.c compat: remove compat_printk() 2016-09-27 21:20:53 -04:00
coredump.c coredump: fix unfreezable coredumping task 2016-11-11 08:12:37 -08:00
dax.c thp: reduce usage of huge zero page's atomic counter 2016-10-07 18:46:28 -07:00
dcache.c
dcookies.c
direct-io.c consistent treatment of EFAULT on O_DIRECT read/write 2016-10-03 20:38:55 -04:00
drop_caches.c
eventfd.c
eventpoll.c
exec.c mm: replace get_user_pages_remote() write/force parameters with gup_flags 2016-10-19 08:12:02 -07:00
fcntl.c
fhandle.c
file_table.c
file.c fs/file: more unsigned file descriptors 2016-09-27 18:47:38 -04:00
filesystems.c
fs_pin.c
fs_struct.c
fs-writeback.c
inode.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
internal.h Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 13:04:49 -07:00
ioctl.c vfs: cap dedupe request structure size at PAGE_SIZE 2016-09-15 13:29:52 -07:00
iomap.c fs: Do to trim high file position bits in iomap_page_mkwrite_actor 2016-10-24 14:20:25 +11:00
Kconfig mm/hugetlb: introduce ARCH_HAS_GIGANTIC_PAGE 2016-10-07 18:46:29 -07:00
Kconfig.binfmt
libfs.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
locks.c locking, fs/locks: Add missing file_sem locks 2016-10-18 12:21:28 +02:00
Makefile
mbcache.c mbcache: fix to detect failure of register_shrinker 2016-08-31 11:44:36 -04:00
mount.h mnt: Add a per mount namespace limit on the number of mounts 2016-09-30 12:46:48 -05:00
mpage.c
namei.c Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs 2016-10-14 17:23:33 -07:00
namespace.c This adds a new gcc plugin named "latent_entropy". It is designed to 2016-10-15 10:03:15 -07:00
no-block.c
nsfs.c net: add an ioctl to get a socket network namespace 2016-10-31 10:56:36 -04:00
open.c xfs: reflink update for 4.9-rc1 2016-10-13 20:28:22 -07:00
pipe.c pipe: cap initial pipe capacity according to pipe-max-size limit 2016-10-11 15:06:32 -07:00
pnode.c mnt: Add a per mount namespace limit on the number of mounts 2016-09-30 12:46:48 -05:00
pnode.h mnt: Add a per mount namespace limit on the number of mounts 2016-09-30 12:46:48 -05:00
posix_acl.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-10-10 20:16:43 -07:00
proc_namespace.c
read_write.c iov_iter: kernel-doc import_iovec() and rw_copy_check_uvector() 2016-10-14 20:00:34 -04:00
readdir.c
select.c fs/select: add vmalloc fallback for select(2) 2016-10-11 15:06:30 -07:00
seq_file.c seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char 2016-10-07 18:46:30 -07:00
signalfd.c
splice.c splice: remove detritus from generic_file_splice_read() 2016-11-10 18:32:13 -05:00
stack.c
stat.c
statfs.c
super.c fs/super.c: don't fool lockdep in freeze_super() and thaw_super() paths 2016-10-14 20:41:59 -04:00
sync.c
timerfd.c
userfaultfd.c
utimes.c Merge remote-tracking branch 'jk/vfs' into work.misc 2016-10-08 11:06:08 -04:00
xattr.c vfs: Remove {get,set,remove}xattr inode operations 2016-10-07 21:48:36 -04:00