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c2452f3278
android_kernel_xiaomi_sm8350/fs
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Nick Piggin c2452f3278 shrink struct dentry 
struct dentry is one of the most critical structures in the kernel. So it's
sad to see it going neglected.

With CONFIG_PROFILING turned on (which is probably the common case at least
for distros and kernel developers), sizeof(struct dcache) == 208 here
(64-bit). This gives 19 objects per slab.

I packed d_mounted into a hole, and took another 4 bytes off the inline
name length to take the padding out from the end of the structure. This
shinks it to 200 bytes. I could have gone the other way and increased the
length to 40, but I'm aiming for a magic number, read on...

I then got rid of the d_cookie pointer. This shrinks it to 192 bytes. Rant:
why was this ever a good idea? The cookie system should increase its hash
size or use a tree or something if lookups are a problem. Also the "fast
dcookie lookups" in oprofile should be moved into the dcookie code -- how
can oprofile possibly care about the dcookie_mutex? It gets dropped after
get_dcookie() returns so it can't be providing any sort of protection.

At 192 bytes, 21 objects fit into a 4K page, saving about 3MB on my system
with ~140 000 entries allocated. 192 is also a multiple of 64, so we get
nice cacheline alignment on 64 and 32 byte line systems -- any given dentry
will now require 3 cachelines to touch all fields wheras previously it
would require 4.

I know the inline name size was chosen quite carefully, however with the
reduction in cacheline footprint, it should actually be just about as fast
to do a name lookup for a 36 character name as it was before the patch (and
faster for other sizes). The memory footprint savings for names which are
<= 32 or > 36 bytes long should more than make up for the memory cost for
33-36 byte names.

Performance is a feature...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-12-31 18:07:38 -05:00
..
9p Merge branch 'next' into for-linus 2008-12-25 11:40:09 +11:00
adfs vfs: Use const for kernel parser table 2008-10-13 10:10:37 -07:00
affs CRED: Wrap task credential accesses in the AFFS filesystem 2008-11-14 10:38:45 +11:00
afs fs: replace NIPQUAD() 2008-10-31 00:56:28 -07:00
autofs CRED: Wrap task credential accesses in the autofs filesystem 2008-11-14 10:38:45 +11:00
autofs4 Merge branch 'master' into next 2008-11-14 11:29:12 +11:00
befs befs: annotate fs32 on tests for superblock endianness 2008-10-16 11:21:46 -07:00
bfs CRED: Wrap task credential accesses in the BFS filesystem 2008-11-14 10:38:47 +11:00
cifs cifs: update for new IP4/6 address printing 2008-12-28 16:29:58 -08:00
coda coda: fix creds reference 2008-11-20 08:11:52 +11:00
configfs [PATCH] assorted path_lookup() -> kern_path() conversions 2008-10-23 05:12:52 -04:00
cramfs cramfs: fix named-pipe handling 2008-08-20 15:40:32 -07:00
debugfs integrity: special fs magic 2008-10-13 09:47:43 +11:00
devpts CRED: Wrap task credential accesses in the devpts filesystem 2008-11-14 10:38:49 +11:00
dlm fix warning in fs/dlm/netlink.c 2008-11-25 16:51:45 -08:00
ecryptfs Merge branch 'master' into next 2008-12-04 17:16:36 +11:00
efs [PATCH] switch all filesystems over to d_obtain_alias 2008-10-23 05:13:01 -04:00
exportfs Merge branch 'next' into for-linus 2008-12-25 11:40:09 +11:00
ext2 CRED: Wrap task credential accesses in the Ext2 filesystem 2008-11-14 10:38:50 +11:00
ext3 Merge branch 'master' into next 2008-11-14 11:29:12 +11:00
ext4 Get rid of CONFIG_LSF 2008-12-29 08:29:51 +01:00
fat Merge branch 'master' into next 2008-11-14 11:29:12 +11:00
freevxfs
fuse CRED: Use RCU to access another task's creds and to release a task's own creds 2008-11-14 10:39:19 +11:00
gfs2 CRED: Wrap task credential accesses in the GFS2 filesystem 2008-11-14 10:38:53 +11:00
hfs CRED: Wrap task credential accesses in the HFS filesystem 2008-11-14 10:38:54 +11:00
hfsplus CRED: Wrap task credential accesses in the HFSplus filesystem 2008-11-14 10:38:54 +11:00
hostfs hostfs: fix a duplicated global function name 2008-11-19 18:50:00 -08:00
hpfs CRED: Wrap task credential accesses in the HPFS filesystem 2008-11-14 10:38:55 +11:00
hppfs CRED: Use creds in file structs 2008-11-14 10:39:25 +11:00
hugetlbfs CRED: Wrap current->cred and a few other accessors 2008-11-14 10:39:18 +11:00
isofs [PATCH] switch all filesystems over to d_obtain_alias 2008-10-23 05:13:01 -04:00
jbd jbd: don't give up looking for space so easily in __log_wait_for_space 2008-11-06 22:37:59 -05:00
jbd2 jbd2: don't give up looking for space so easily in __jbd2_log_wait_for_space 2008-11-06 22:38:07 -05:00
jffs2 Merge git://git.infradead.org/mtd-2.6 2008-11-06 15:43:13 -08:00
jfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shaggy/jfs-2.6 2008-12-30 17:33:33 -08:00
lockd Merge branch 'devel' into next 2008-12-30 16:51:43 -05:00
minix CRED: Wrap task credential accesses in the Minix filesystem 2008-11-14 10:38:57 +11:00
ncpfs CRED: Wrap task credential accesses in the NCPFS filesystem 2008-11-14 10:38:58 +11:00
nfs Merge branch 'devel' into next 2008-12-30 16:51:43 -05:00
nfs_common SUNRPC: nfsacl_encode/nfsacl_decode should be exported as GPL-only 2008-12-23 15:21:32 -05:00
nfsd Merge branch 'devel' into next 2008-12-30 16:51:43 -05:00
nls remove CONFIG_KMOD from fs 2008-10-17 02:38:36 +11:00
ntfs ntfs: don't fool kernel-doc 2008-12-01 19:55:25 -08:00
ocfs2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2008-12-28 12:49:40 -08:00
omfs CRED: Wrap task credential accesses in the OMFS filesystem 2008-11-14 10:38:59 +11:00
openpromfs [PATCH] fix ->llseek for more directories 2008-10-23 05:13:21 -04:00
partitions block/md: fix md autodetection 2008-11-18 15:08:56 +01:00
proc Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-12-30 16:20:19 -08:00
qnx4
ramfs CRED: Wrap task credential accesses in the RAMFS filesystem 2008-11-14 10:39:00 +11:00
reiserfs CRED: Wrap task credential accesses in the ReiserFS filesystem 2008-11-14 10:39:01 +11:00
romfs
smbfs CRED: Wrap current->cred and a few other accessors 2008-11-14 10:39:18 +11:00
sysfs [PATCH] fix ->llseek for more directories 2008-10-23 05:13:21 -04:00
sysv CRED: Wrap task credential accesses in the SYSV filesystem 2008-11-14 10:39:02 +11:00
ubifs Merge branch 'master' into next 2008-12-04 17:16:36 +11:00
udf Merge branch 'master' into next 2008-12-04 17:16:36 +11:00
ufs CRED: Wrap task credential accesses in the UFS filesystem 2008-11-14 10:39:04 +11:00
xfs [XFS] Fix merge failures 2008-12-29 16:47:18 +11:00
aio.c aio: make the lookup_ioctx() lockless 2008-12-29 08:29:50 +01:00
anon_inodes.c CRED: Wrap task credential accesses in the filesystem subsystem 2008-11-14 10:39:05 +11:00
attr.c CRED: Wrap task credential accesses in the filesystem subsystem 2008-11-14 10:39:05 +11:00
bad_inode.c
binfmt_aout.c CRED: Make execve() take advantage of copy-on-write credentials 2008-11-14 10:39:24 +11:00
binfmt_elf_fdpic.c CRED: Make execve() take advantage of copy-on-write credentials 2008-11-14 10:39:24 +11:00
binfmt_elf.c Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6 2008-12-28 12:33:21 -08:00
binfmt_em86.c Allow recursion in binfmt_script and binfmt_misc 2008-10-16 11:21:38 -07:00
binfmt_flat.c CRED: Make execve() take advantage of copy-on-write credentials 2008-11-14 10:39:24 +11:00
binfmt_misc.c Allow recursion in binfmt_script and binfmt_misc 2008-10-16 11:21:38 -07:00
binfmt_script.c Allow recursion in binfmt_script and binfmt_misc 2008-10-16 11:21:38 -07:00
binfmt_som.c CRED: Make execve() take advantage of copy-on-write credentials 2008-11-14 10:39:24 +11:00
bio-integrity.c bio: allow individual slabs in the bio_set 2008-12-29 08:29:23 +01:00
bio.c bio: get rid of bio_vec clearing 2008-12-29 08:29:53 +01:00
block_dev.c [PATCH 1/2] kill FMODE_NDELAY_NOW 2008-12-04 04:22:57 -05:00
buffer.c block: Supress Buffer I/O errors when SCSI REQ_QUIET flag set 2008-12-29 08:28:44 +01:00
char_dev.c [PATCH] tidy up chrdev_open 2008-10-23 05:12:59 -04:00
compat_binfmt_elf.c
compat_ioctl.c
compat.c CRED: Make execve() take advantage of copy-on-write credentials 2008-11-14 10:39:24 +11:00
dcache.c shrink struct dentry 2008-12-31 18:07:38 -05:00
dcookies.c shrink struct dentry 2008-12-31 18:07:38 -05:00
direct-io.c Remove Andrew Morton's old email accounts 2008-10-16 11:21:32 -07:00
dnotify.c
dquot.c CRED: Wrap task credential accesses in the filesystem subsystem 2008-11-14 10:39:05 +11:00
drop_caches.c
eventfd.c
eventpoll.c epoll: introduce resource usage limits 2008-12-01 19:55:24 -08:00
exec.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-12-30 16:16:21 -08:00
fcntl.c Merge branch 'next' into for-linus 2008-12-25 11:40:09 +11:00
fifo.c [PATCH] introduce fmode_t, do annotations 2008-10-21 07:47:06 -04:00
file_table.c CRED: Use creds in file structs 2008-11-14 10:39:25 +11:00
file.c
filesystems.c proc: move /proc/filesystems to fs/filesystems.c 2008-10-23 14:27:09 +04:00
fs-writeback.c Remove Andrew Morton's old email accounts 2008-10-16 11:21:32 -07:00
generic_acl.c
inode.c fs: xfs needs inode_wait to be exported 2008-11-10 17:06:05 +11:00
inotify_user.c fs: reorder struct inotify_device on 64bits to remove padding 2008-12-31 18:07:37 -05:00
inotify.c inotify: fix IN_ONESHOT unmount event watcher 2008-12-10 08:01:53 -08:00
internal.h CRED: Make execve() take advantage of copy-on-write credentials 2008-11-14 10:39:24 +11:00
ioctl.c Fix a race condition in FASYNC handling 2008-12-05 15:35:10 -08:00
ioprio.c CRED: Use RCU to access another task's creds and to release a task's own creds 2008-11-14 10:39:19 +11:00
Kconfig [patch 1/3] FS_MBCACHE: don't needlessly make it built-in 2008-10-23 05:13:26 -04:00
Kconfig.binfmt add CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS 2008-10-20 08:52:39 -07:00
libfs.c fs: remove prepare_write/commit_write 2008-10-30 11:38:45 -07:00
locks.c CRED: Wrap task credential accesses in the filesystem subsystem 2008-11-14 10:39:05 +11:00
Makefile fat: move fs/vfat/* and fs/msdos/* to fs/fat 2008-11-06 15:41:20 -08:00
mbcache.c
mpage.c Remove Andrew Morton's old email accounts 2008-10-16 11:21:32 -07:00
namei.c introduce new LSM hooks where vfsmount is available. 2008-12-31 18:07:37 -05:00
namespace.c Merge branch 'master' into next 2008-11-14 11:29:12 +11:00
nfsctl.c nfsctl: add headers for credentials 2008-11-20 08:11:55 +11:00
no-block.c
open.c introduce new LSM hooks where vfsmount is available. 2008-12-31 18:07:37 -05:00
pipe.c CRED: Wrap task credential accesses in the filesystem subsystem 2008-11-14 10:39:05 +11:00
pnode.c
pnode.h
posix_acl.c CRED: Wrap task credential accesses in the filesystem subsystem 2008-11-14 10:39:05 +11:00
quota_v1.c
quota_v2.c
quota.c CRED: Wrap task credential accesses in the filesystem subsystem 2008-11-14 10:39:05 +11:00
read_write.c [PATCH] generic_file_llseek tidyups 2008-10-23 05:12:59 -04:00
read_write.h
readdir.c [PATCH] prepare vfs_readdir() callers to returning filldir result 2008-10-23 05:13:10 -04:00
select.c select: deal with math overflow from borderline valid userland data 2008-10-26 11:22:08 -07:00
seq_file.c vfs, seqfile: export mangle_path() generally 2008-11-28 18:07:10 +01:00
signalfd.c
splice.c fs: remove prepare_write/commit_write 2008-10-30 11:38:45 -07:00
stack.c
stat.c
super.c security: pass mount flags to security_sb_kern_mount() 2008-12-20 09:02:39 +11:00
sync.c
timerfd.c hrtimer: convert timerfd to the new hrtimer apis 2008-09-05 21:35:09 -07:00
utimes.c
xattr_acl.c
xattr.c