linux/fs
Vivek Haldar 556b27abf7 ext4: do not normalize block requests from fallocate()
Currently, an fallocate request of size slightly larger than a power of
2 is turned into two block requests, each a power of 2, with the extra
blocks pre-allocated for future use. When an application calls
fallocate, it already has an idea about how large the file may grow so
there is usually little benefit to reserve extra blocks on the
preallocation list. This reduces disk fragmentation.

Tested: fsstress. Also verified manually that fallocat'ed files are
contiguously laid out with this change (whereas without it they begin at
power-of-2 boundaries, leaving blocks in between). CPU usage of
fallocate is not appreciably higher.  In a tight fallocate loop, CPU
usage hovers between 5%-8% with this change, and 5%-7% without it.

Using a simulated file system aging program which the file system to
70%, the percentage of free extents larger than 8MB (as measured by
e2freefrag) increased from 38.8% without this change, to 69.4% with
this change.

Signed-off-by: Vivek Haldar <haldar@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-05-25 07:41:54 -04:00
..
9p userns: rename is_owner_or_cap to inode_owner_or_capable 2011-03-23 19:47:13 -07:00
adfs Fix common misspellings 2011-03-31 11:26:23 -03:00
affs Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
afs Fix common misspellings 2011-03-31 11:26:23 -03:00
autofs4 Fix common misspellings 2011-03-31 11:26:23 -03:00
befs Fix common misspellings 2011-03-31 11:26:23 -03:00
bfs Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
btrfs Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6 2011-04-07 11:14:49 -07:00
cachefiles Fix common misspellings 2011-03-31 11:26:23 -03:00
ceph Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6 2011-04-07 11:14:49 -07:00
cifs Fix common misspellings 2011-03-31 11:26:23 -03:00
coda codafs: fix build break when CONFIG_PROC_SYSCTL=n 2011-03-25 17:45:16 -07:00
configfs Fix common misspellings 2011-03-31 11:26:23 -03:00
cramfs
debugfs
devpts fs/devpts/inode.c: correctly check d_alloc_name() return code in devpts_pty_new() 2011-03-22 17:44:17 -07:00
dlm Fix common misspellings 2011-03-31 11:26:23 -03:00
ecryptfs Fix common misspellings 2011-03-31 11:26:23 -03:00
efs block: remove per-queue plugging 2011-03-10 08:52:07 +01:00
exofs Fix common misspellings 2011-03-31 11:26:23 -03:00
exportfs vfs: Add open by file handle support 2011-03-15 02:21:44 -04:00
ext2 Fix common misspellings 2011-03-31 11:26:23 -03:00
ext3 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6 2011-04-08 07:35:17 -07:00
ext4 ext4: do not normalize block requests from fallocate() 2011-05-25 07:41:54 -04:00
fat Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
freevxfs Fix common misspellings 2011-03-31 11:26:23 -03:00
fscache
fuse Fix common misspellings 2011-03-31 11:26:23 -03:00
gfs2 Fix common misspellings 2011-03-31 11:26:23 -03:00
hfs Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
hfsplus Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
hostfs
hpfs Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
hppfs
hugetlbfs mm: hugetlbfs: change remove_from_page_cache 2011-03-22 17:44:02 -07:00
isofs Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
jbd Fix common misspellings 2011-03-31 11:26:23 -03:00
jbd2 jbd2: Fix comment to match the code in jbd2__journal_start() 2011-05-24 17:09:58 -04:00
jffs2 Fix common misspellings 2011-03-31 11:26:23 -03:00
jfs Fix common misspellings 2011-03-31 11:26:23 -03:00
lockd
logfs Fix common misspellings 2011-03-31 11:26:23 -03:00
minix Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
ncpfs Fix common misspellings 2011-03-31 11:26:23 -03:00
nfs Merge branch 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6 2011-04-08 11:47:35 -07:00
nfs_common Fix common misspellings 2011-03-31 11:26:23 -03:00
nfsd Merge branch 'for-2.6.39' of git://linux-nfs.org/~bfields/linux 2011-04-11 15:45:17 -07:00
nilfs2 fs: export empty_aops 2011-04-05 23:51:48 +02:00
nls
notify Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6 2011-04-07 11:14:49 -07:00
ntfs Fix common misspellings 2011-03-31 11:26:23 -03:00
ocfs2 Fix common misspellings 2011-03-31 11:26:23 -03:00
omfs Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
openpromfs
partitions Fix common misspellings 2011-03-31 11:26:23 -03:00
proc Fix common misspellings 2011-03-31 11:26:23 -03:00
pstore Fix common misspellings 2011-03-31 11:26:23 -03:00
qnx4 block: remove per-queue plugging 2011-03-10 08:52:07 +01:00
quota Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6 2011-04-08 07:35:17 -07:00
ramfs
reiserfs Fix common misspellings 2011-03-31 11:26:23 -03:00
romfs
squashfs Fix common misspellings 2011-03-31 11:26:23 -03:00
sysfs
sysv Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
ubifs Merge branch 'for-linus' of git://git.infradead.org/ubifs-2.6 2011-04-07 11:31:03 -07:00
udf Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
ufs Merge branch 'for-linus2' of git://git.profusion.mobi/users/lucas/linux-2.6 2011-04-07 11:14:49 -07:00
xfs Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs 2011-04-11 15:48:57 -07:00
aio.c Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
anon_inodes.c
attr.c Fix common misspellings 2011-03-31 11:26:23 -03:00
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2011-03-23 20:51:42 -07:00
binfmt_em86.c
binfmt_flat.c Fix common misspellings 2011-03-31 11:26:23 -03:00
binfmt_misc.c
binfmt_script.c
binfmt_som.c
bio-integrity.c block: Require subsystems to explicitly allocate bio_set integrity mempool 2011-03-17 11:11:05 +01:00
bio.c Fix common misspellings 2011-03-31 11:26:23 -03:00
block_dev.c Fix common misspellings 2011-03-31 11:26:23 -03:00
buffer.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2011-03-24 19:01:30 -07:00
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c
compat.c select: remove unused MAX_SELECT_SECONDS 2011-03-21 00:16:08 -04:00
dcache.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2011-03-18 10:51:11 -07:00
dcookies.c
direct-io.c Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
drop_caches.c fs: move i_sb_list out from under inode_lock 2011-03-24 21:16:32 -04:00
eventfd.c
eventpoll.c Fix common misspellings 2011-03-31 11:26:23 -03:00
exec.c Small typo fix... 2011-03-21 00:16:09 -04:00
fcntl.c userns: rename is_owner_or_cap to inode_owner_or_capable 2011-03-23 19:47:13 -07:00
fhandle.c vfs: Add open by file handle support 2011-03-15 02:21:44 -04:00
fifo.c Filesystem: fifo: Fixed coding style issue. 2011-03-21 00:16:09 -04:00
file_table.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2011-03-16 13:26:17 -07:00
file.c
filesystems.c
fs_struct.c
fs-writeback.c Fix common misspellings 2011-03-31 11:26:23 -03:00
generic_acl.c userns: rename is_owner_or_cap to inode_owner_or_capable 2011-03-23 19:47:13 -07:00
inode.c fs: export empty_aops 2011-04-05 23:51:48 +02:00
internal.h fs: move i_wb_list out from under inode_lock 2011-03-24 21:17:51 -04:00
ioctl.c vfs: cleanup do_vfs_ioctl() 2011-03-21 00:16:08 -04:00
ioprio.c
Kconfig Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6 2011-03-16 19:01:29 -07:00
Kconfig.binfmt
libfs.c
locks.c Merge branch 'for-2.6.39' of git://linux-nfs.org/~bfields/linux 2011-03-24 08:20:39 -07:00
Makefile Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6 2011-03-16 19:01:29 -07:00
mbcache.c Fix common misspellings 2011-03-31 11:26:23 -03:00
mpage.c fs: make mpage read/write_pages() plug 2011-03-10 08:52:26 +01:00
namei.c Fix common misspellings 2011-03-31 11:26:23 -03:00
namespace.c fs: use appropriate printk priority levels 2011-03-22 17:44:10 -07:00
nfsctl.c open-style analog of vfs_path_lookup() 2011-03-14 09:15:28 -04:00
no-block.c
open.c fs: Use BUG_ON(!mnt) at dentry_open(). 2011-03-21 01:10:41 -04:00
pipe.c
pnode.c
pnode.h
posix_acl.c
read_write.c
read_write.h
readdir.c
select.c select: remove unused MAX_SELECT_SECONDS 2011-03-21 00:16:08 -04:00
seq_file.c
signalfd.c
splice.c
stack.c
stat.c readlinkat(), fchownat() and fstatat() with empty relative pathnames 2011-03-15 02:21:45 -04:00
statfs.c clean statfs-like syscalls up 2011-03-14 09:15:28 -04:00
super.c Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
sync.c Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
timerfd.c
utimes.c userns: rename is_owner_or_cap to inode_owner_or_capable 2011-03-23 19:47:13 -07:00
xattr_acl.c
xattr.c userns: rename is_owner_or_cap to inode_owner_or_capable 2011-03-23 19:47:13 -07:00