linux/fs
Vadim Lobanov 5466b456ed [PATCH] fdtable: Implement new pagesize-based fdtable allocator
This patch provides an improved fdtable allocation scheme, useful for
expanding fdtable file descriptor entries.  The main focus is on the fdarray,
as its memory usage grows 128 times faster than that of an fdset.

The allocation algorithm sizes the fdarray in such a way that its memory usage
increases in easy page-sized chunks. The overall algorithm expands the allowed
size in powers of two, in order to amortize the cost of invoking vmalloc() for
larger allocation sizes. Namely, the following sizes for the fdarray are
considered, and the smallest that accommodates the requested fd count is
chosen:

    pagesize / 4
    pagesize / 2
    pagesize      <- memory allocator switch point
    pagesize * 2
    pagesize * 4
    ...etc...

Unlike the current implementation, this allocation scheme does not require a
loop to compute the optimal fdarray size, and can be done in efficient
straightline code.

Furthermore, since the fdarray overflows the pagesize boundary long before any
of the fdsets do, it makes sense to optimize run-time by allocating both
fdsets in a single swoop.  Even together, they will still be, by far, smaller
than the fdarray.  The fdtable->open_fds is now used as the anchor for the
fdset memory allocation.

Signed-off-by: Vadim Lobanov <vlobanov@speakeasy.net>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-10 09:57:22 -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] rename struct namespace to struct mnt_namespace 2006-12-08 08:28:51 -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] io-accounting-read-accounting cifs fix 2006-12-10 09:55:41 -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] rename struct namespace to struct mnt_namespace 2006-12-08 08:28:51 -08:00
nfs_common [PATCH] nfs_common endianness annotations 2006-10-20 10:26:41 -07:00
nfsd [PATCH] nfsd: replace kmalloc+memset with kcalloc + simplify NULL check 2006-12-08 08:29:02 -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 [MIPS] Rename SNI_RM200_PCI to just SNI_RM preparing for more RM machines 2006-12-09 01:03:58 +00:00
proc [PATCH] io-accounting: report in procfs 2006-12-10 09:55:41 -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] rename struct namespace to struct mnt_namespace 2006-12-08 08:28:51 -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] dio: only call aio_complete() after returning -EIOCBQUEUED 2006-12-10 09:57:21 -08:00
aio.c [PATCH] aio: remove ki_retried debugging member 2006-12-07 08:39:46 -08:00
attr.c [PATCH] capable/capability.h (fs/) 2006-01-11 18:42:13 -08:00
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] add process_session() helper routine 2006-12-08 08:28:51 -08:00
binfmt_elf.c [PATCH] add process_session() helper routine 2006-12-08 08:28:51 -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] io-accounting: write-cancel accounting 2006-12-10 09:55:41 -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] fdtable: Make fdarray and fdsets equal in size 2006-12-10 09:57:22 -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] dio: lock refcount operations 2006-12-10 09:57:21 -08:00
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] fdtable: Make fdarray and fdsets equal in size 2006-12-10 09:57:22 -08:00
fcntl.c [PATCH] fdtable: Make fdarray and fdsets equal in size 2006-12-10 09:57:22 -08:00
fifo.c [PATCH] pipe.c/fifo.c code cleanups 2006-04-11 13:53:33 +02:00
file_table.c [PATCH] VFS: change struct file to use struct path 2006-12-08 08:28:41 -08:00
file.c [PATCH] fdtable: Implement new pagesize-based fdtable allocator 2006-12-10 09:57:22 -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] rename struct namespace to struct mnt_namespace 2006-12-08 08:28:51 -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] fdtable: Make fdarray and fdsets equal in size 2006-12-10 09:57:22 -08:00
pipe.c [PATCH] VFS: change struct file to use struct path 2006-12-08 08:28:41 -08:00
pnode.c [PATCH] rename struct namespace to struct mnt_namespace 2006-12-08 08:28:51 -08:00
pnode.h [PATCH] rename struct namespace to struct mnt_namespace 2006-12-08 08:28:51 -08:00
posix_acl.c [PATCH] kmemdup: some users 2006-10-01 00:39:19 -07:00
quota_v1.c
quota_v2.c [PATCH] sem2mutex: quota 2006-03-23 07:38:11 -08:00
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] fdtable: Make fdarray and fdsets equal in size 2006-12-10 09:57:22 -08:00
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