David Howells f0d1b0b30d [PATCH] LOG2: Implement a general integer log2 facility in the kernel ... This facility provides three entry points: ilog2() Log base 2 of unsigned long ilog2_u32() Log base 2 of u32 ilog2_u64() Log base 2 of u64 These facilities can either be used inside functions on dynamic data: int do_something(long q) { ...; y = ilog2(x) ...; } Or can be used to statically initialise global variables with constant values: unsigned n = ilog2(27); When performing static initialisation, the compiler will report "error: initializer element is not constant" if asked to take a log of zero or of something not reducible to a constant. They treat negative numbers as unsigned. When not dealing with a constant, they fall back to using fls() which permits them to use arch-specific log calculation instructions - such as BSR on x86/x86_64 or SCAN on FRV - if available. [akpm@osdl.org: MMC fix] Signed-off-by: David Howells <dhowells@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: David Howells <dhowells@redhat.com> Cc: Wojtek Kaniewski <wojtekka@toxygen.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>		2006-12-08 08:28:51 -08:00
..
9p	[PATCH] 9p: change uses of f_{dentry,vfsmnt} to use f_path	2006-12-08 08:28:43 -08:00
adfs	[PATCH] struct path: convert adfs	2006-12-08 08:28:43 -08:00
affs	[PATCH] affs: change uses of f_{dentry, vfsmnt} to use f_path	2006-12-08 08:28:43 -08:00
afs	[PATCH] struct path: convert afs	2006-12-08 08:28:43 -08:00
autofs	[PATCH] autofs: change uses of f_{dentry, vfsmnt} to use f_path	2006-12-08 08:28:43 -08:00
autofs4	[PATCH] autofs4: change uses of f_{dentry, vfsmnt} to use f_path	2006-12-08 08:28:43 -08:00
befs	[PATCH] struct path: convert befs	2006-12-08 08:28:44 -08:00
bfs	[PATCH] struct path: convert bfs	2006-12-08 08:28:44 -08:00
cifs	[PATCH] cifs: change uses of f_{dentry, vfsmnt} to use f_path	2006-12-08 08:28:43 -08:00
coda	[PATCH] struct path: convert coda	2006-12-08 08:28:44 -08:00
configfs	[PATCH] configfs: change uses of f_{dentry, vfsmnt} to use f_path	2006-12-08 08:28:43 -08:00
cramfs	[PATCH] struct path: convert cramfs	2006-12-08 08:28:44 -08:00
debugfs	[PATCH] debugfs: add header file	2006-11-25 13:28:33 -08:00
devpts	[PATCH] inode-diet: Eliminate i_blksize from the inode structure	2006-09-27 08:26:18 -07:00
dlm	Merge master.kernel.org:/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw	2006-12-07 09:13:20 -08:00
ecryptfs	[PATCH] ecryptfs: change uses of f_{dentry, vfsmnt} to use f_path	2006-12-08 08:28:43 -08:00
efs	[PATCH] struct path: convert efs	2006-12-08 08:28:45 -08:00
exportfs	[PATCH] VFS: Make filldir_t and struct kstat deal in 64-bit inode numbers	2006-10-03 08:03:40 -07:00
ext2	[PATCH] LOG2: Implement a general integer log2 facility in the kernel	2006-12-08 08:28:51 -08:00
ext3	[PATCH] LOG2: Implement a general integer log2 facility in the kernel	2006-12-08 08:28:51 -08:00
ext4	[PATCH] ext4: change uses of f_{dentry, vfsmnt} to use f_path	2006-12-08 08:28:41 -08:00
fat	[PATCH] fat: change uses of f_{dentry,vfsmnt} to use f_path	2006-12-08 08:28:41 -08:00
freevxfs	[PATCH] struct path: convert freevxfs	2006-12-08 08:28:45 -08:00
fuse	[PATCH] struct path: convert fuse	2006-12-08 08:28:45 -08:00
gfs2	[PATCH] struct path: convert gfs2	2006-12-08 08:28:45 -08:00
hfs	[PATCH] struct path: convert hfs	2006-12-08 08:28:45 -08:00
hfsplus	[PATCH] struct path: convert hfsplus	2006-12-08 08:28:45 -08:00
hostfs	[PATCH] struct path: convert hostfs	2006-12-08 08:28:45 -08:00
hpfs	[PATCH] struct path: convert hpfs	2006-12-08 08:28:45 -08:00
hppfs	[PATCH] struct path: convert hppfs	2006-12-08 08:28:45 -08:00
hugetlbfs	[PATCH] struct path: convert hugetlbfs	2006-12-08 08:28:45 -08:00
isofs	[PATCH] isofs: change uses of f_{dentry, vfsmnt} to use f_path	2006-12-08 08:28:41 -08:00
jbd	[PATCH] make fs/jbd/transaction.c:__journal_temp_unlink_buffer() static	2006-12-07 08:39:40 -08:00
jbd2	[PATCH] jbd2: wait for already submitted t_sync_datalist buffer to complete	2006-12-07 08:39:42 -08:00
jffs	[PATCH] struct path: convert jffs	2006-12-08 08:28:46 -08:00
jffs2	[PATCH] struct path: convert jffs2	2006-12-08 08:28:46 -08:00
jfs	[PATCH] struct path: convert jfs	2006-12-08 08:28:46 -08:00
lockd	[PATCH] struct path: convert lockd	2006-12-08 08:28:47 -08:00
minix	[PATCH] struct path: convert minix	2006-12-08 08:28:47 -08:00
msdos	[PATCH] fat: add fat_getattr()	2006-11-16 11:43:38 -08:00
ncpfs	[PATCH] struct path: convert ncpfs	2006-12-08 08:28:48 -08:00
nfs	[PATCH] nfs: change uses of f_{dentry,vfsmnt} to use f_path	2006-12-08 08:28:41 -08:00
nfs_common	[PATCH] nfs_common endianness annotations	2006-10-20 10:26:41 -07:00
nfsd	[PATCH] nfsd: change uses of f_{dentry, vfsmnt} to use f_path	2006-12-08 08:28:42 -08:00
nls	[PATCH] fs: make nls_cp936.c handle some U00XY characters and U20AC correctly	2006-12-07 08:39:46 -08:00
ntfs	[PATCH] ntfs: change uses of f_{dentry, vfsmnt} to use f_path	2006-12-08 08:28:42 -08:00
ocfs2	[PATCH] struct path: convert ocfs2	2006-12-08 08:28:48 -08:00
openpromfs	[PATCH] struct path: convert openpromfs	2006-12-08 08:28:48 -08:00
partitions	[PATCH] Fix check_partition routines	2006-12-07 08:39:30 -08:00
proc	[PATCH] proc: change uses of f_{dentry, vfsmnt} to use f_path	2006-12-08 08:28:41 -08:00
qnx4	[PATCH] struct path: convert qnx4	2006-12-08 08:28:48 -08:00
ramfs	[PATCH] struct path: convert ramfs	2006-12-08 08:28:49 -08:00
reiserfs	[PATCH] struct path: convert reiserfs	2006-12-08 08:28:49 -08:00
romfs	[PATCH] struct path: convert romfs	2006-12-08 08:28:49 -08:00
smbfs	[PATCH] struct path: convert smbfs	2006-12-08 08:28:49 -08:00
sysfs	[PATCH] sysfs: change uses of f_{dentry, vfsmnt} to use f_path	2006-12-08 08:28:41 -08:00
sysv	[PATCH] struct path: convert sysv	2006-12-08 08:28:50 -08:00
udf	[PATCH] struct path: convert udf	2006-12-08 08:28:50 -08:00
ufs	[PATCH] struct path: convert ufs	2006-12-08 08:28:50 -08:00
vfat	[PATCH] fat: add fat_getattr()	2006-11-16 11:43:38 -08:00
xfs	[PATCH] xfs: change uses of f_{dentry,vfsmnt} to use f_path	2006-12-08 08:28:43 -08:00
aio.c	[PATCH] aio: remove ki_retried debugging member	2006-12-07 08:39:46 -08:00
attr.c
bad_inode.c	[PATCH] Remove readv/writev methods and use aio_read/aio_write instead	2006-10-01 00:39:28 -07:00
binfmt_aout.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
binfmt_elf_fdpic.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
binfmt_elf.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
binfmt_em86.c
binfmt_flat.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
binfmt_misc.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
binfmt_script.c
binfmt_som.c	[PARISC] Fix fs/binfmt_som.c	2006-10-04 06:51:26 -06:00
bio.c	[PATCH] slab: remove kmem_cache_t	2006-12-07 08:39:25 -08:00
block_dev.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
buffer.c	[PATCH] hotplug CPU: clean up hotcpu_notifier() use	2006-12-07 08:39:39 -08:00
char_dev.c	[PATCH] BLOCK: Move extern declarations out of fs/*.c into header files [try #6]	2006-09-30 20:52:18 +02:00
compat_ioctl.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
compat.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
dcache.c	[PATCH] dcache: avoid RCU for never-hashed dentries	2006-12-07 08:39:41 -08:00
dcookies.c	[PATCH] slab: remove kmem_cache_t	2006-12-07 08:39:25 -08:00
direct-io.c	[PATCH] lockdep: annotate direct io	2006-07-03 15:27:06 -07:00
dnotify.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
dquot.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
drop_caches.c
eventpoll.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
exec.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
fcntl.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
fifo.c
file_table.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
file.c	[PATCH] file: kill unnecessary timer in fdtable_defer	2006-12-07 08:39:32 -08:00
filesystems.c	[PATCH] Ban register_filesystem(NULL);	2006-09-29 09:18:20 -07:00
fs-writeback.c	[PATCH] BLOCK: Remove dependence on existence of blockdev_superblock [try #6]	2006-09-30 20:52:26 +02:00
generic_acl.c	[PATCH] Generic infrastructure for acls	2006-09-29 09:18:24 -07:00
inode.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
inotify_user.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
inotify.c	[PATCH] severing fs.h, radix-tree.h -> sched.h	2006-12-04 02:00:24 -05:00
internal.h	[PATCH] CONFIG_BLOCK internal.h cleanups	2006-09-30 20:52:32 +02:00
ioctl.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
ioprio.c	[PATCH] block layer: ioprio_best function fix	2006-10-12 15:09:51 +02:00
Kconfig	Fix typos in doc and comments	2006-11-30 05:32:19 +01:00
Kconfig.binfmt
libfs.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
locks.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
Makefile	[PATCH] fsstack: Introduce fsstack_copy_{attr,inode}_*	2006-12-08 08:28:40 -08:00
mbcache.c	[PATCH] slab: remove kmem_cache_t	2006-12-07 08:39:25 -08:00
mpage.c	[PATCH] BLOCK: Dissociate generic_writepages() from mpage stuff [try #6]	2006-09-30 20:52:26 +02:00
namei.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
namespace.c	[PATCH] slab: remove kmem_cache_t	2006-12-07 08:39:25 -08:00
nfsctl.c	Remove obsolete #include <linux/config.h>	2006-06-30 19:25:36 +02:00
no-block.c	[PATCH] BLOCK: Make it possible to disable the block layer [try #6]	2006-09-30 20:52:31 +02:00
open.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
pipe.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
pnode.c	[PATCH] core: use list_move()	2006-06-26 09:58:17 -07:00
pnode.h
posix_acl.c	[PATCH] kmemdup: some users	2006-10-01 00:39:19 -07:00
quota_v1.c
quota_v2.c
quota.c	[PATCH] BLOCK: Make it possible to disable the block layer [try #6]	2006-09-30 20:52:31 +02:00
read_write.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
read_write.h	[PATCH] Remove readv/writev methods and use aio_read/aio_write instead	2006-10-01 00:39:28 -07:00
readdir.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
select.c	[PATCH] enforce RLIMIT_NOFILE in poll()	2006-09-29 09:18:23 -07:00
seq_file.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
splice.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
stack.c	[PATCH] fsstack: Introduce fsstack_copy_{attr,inode}_*	2006-12-08 08:28:40 -08:00
stat.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
super.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
sync.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00
utimes.c	[PATCH] severing fs.h, radix-tree.h -> sched.h	2006-12-04 02:00:24 -05:00
xattr_acl.c
xattr.c	[PATCH] VFS: change struct file to use struct path	2006-12-08 08:28:41 -08:00