linux/fs
Linus Torvalds 8aab6a2733 vfs: reorganize dput() memory accesses
This is me being a bit OCD after all the dentry optimization work this
merge window: profiles end up showing 'dput()' as a rather expensive
operation, and there were two unrelated bad reasons for that.

The first reason was reading d_lockref.count for debugging purposes,
which touches the lockref cacheline (for reads) before really need to.
More importantly, the debugging test in question is _wrong_, and has
hidden bugs.  It's true that we can only sleep when the count goes down
to zero, but the test as-is hides the much more subtle bug that happens
if we race with somebody else deleting the file.

Anyway we _will_ touch that cacheline, but let's do it for a write and
in the right routine (ie in "lockref_put_or_lock()") which annotates the
costs better.  So remove the misleading debug code.

The other was an unnecessary access to the cacheline that contains the
d_lru list, just to check whether we already were on the LRU list or
not.  This is exactly what we have d_flags for, so that we can avoid
touching extra cache lines for the common case.  So just add another bit
for "is this dentry on the LRU".

Finally, mark the tests properly likely/unlikely, so that the common
fast-paths are dense in the instruction stream.

This makes the profiles look much saner.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-08 13:26:18 -07:00
..
9p Second round of 9p patches for the 3.11 merge window. 2013-07-11 10:21:23 -07:00
adfs Don't pass inode to ->d_hash() and ->d_compare() 2013-06-29 12:57:36 +04:00
affs Don't pass inode to ->d_hash() and ->d_compare() 2013-06-29 12:57:36 +04:00
afs afs: use check_submounts_and_drop() 2013-09-05 16:23:51 -04:00
autofs4 helper for reading ->d_count 2013-07-05 18:59:33 +04:00
befs [readdir] convert befs 2013-06-29 12:56:55 +04:00
bfs bfs: iget_locked() doesn't return an ERR_PTR 2013-08-24 12:10:22 -04:00
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-09-06 09:36:28 -07:00
cachefiles mm: remove lru parameter from __pagevec_lru_add and remove parts of pagevec API 2013-07-03 16:07:31 -07:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2013-07-09 12:39:10 -07:00
cifs direct-io: Handle O_(D)SYNC AIO 2013-09-04 09:23:46 -04:00
coda helper for reading ->d_count 2013-07-05 18:59:33 +04:00
configfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-07-14 11:42:26 -07:00
cramfs [readdir] convert f2fs 2013-06-29 12:56:46 +04:00
debugfs debugfs: debugfs_remove_recursive() must not rely on list_empty(d_subdirs) 2013-07-31 12:16:31 -04:00
devpts
dlm dlm: remove signal blocking 2013-08-12 15:22:43 -05:00
ecryptfs Code cleanups and improved buffer handling during page crypto operations 2013-07-11 10:20:18 -07:00
efivarfs efivarfs: we can use simple_lookup() now 2013-07-14 17:48:35 +04:00
efs efs: iget_locked() doesn't return an ERR_PTR() 2013-08-24 12:10:22 -04:00
exofs Lots of bug fixes, cleanups and optimizations. In the bug fixes 2013-07-02 09:39:34 -07:00
exportfs [readdir] constify ->actor 2013-06-29 12:57:05 +04:00
ext2 [O_TMPFILE] it's still short a few helpers, but infrastructure should be OK now... 2013-06-29 12:57:10 +04:00
ext3 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2013-09-06 09:06:02 -07:00
ext4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2013-09-06 09:36:28 -07:00
f2fs f2fs: optimize gc for better performance 2013-09-05 13:50:32 +09:00
fat fatfs: add FAT_IOCTL_GET_VOLUME_ID 2013-07-09 10:33:25 -07:00
freevxfs [readdir] convert freevxfs 2013-06-29 12:56:53 +04:00
fscache FS-Cache: Don't use spin_is_locked() in assertions 2013-06-19 14:16:47 +01:00
fuse fuse: drop dentry on failed revalidate 2013-09-05 16:23:54 -04:00
gfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-09-07 14:36:57 -07:00
hfs Don't pass inode to ->d_hash() and ->d_compare() 2013-06-29 12:57:36 +04:00
hfsplus Don't pass inode to ->d_hash() and ->d_compare() 2013-06-29 12:57:36 +04:00
hostfs [readdir] convert hostfs 2013-06-29 12:56:59 +04:00
hpfs Merge branch 'hpfs' from Mikulas Patocka 2013-07-04 11:22:55 -07:00
hppfs clean up scary strncpy(dst, src, strlen(src)) uses 2013-07-03 16:07:41 -07:00
hugetlbfs cope with potentially long ->d_dname() output for shmem/hugetlb 2013-08-24 12:10:17 -04:00
isofs isofs: Refuse RW mount of the filesystem instead of making it RO 2013-07-31 22:14:50 +02:00
jbd jbd: use a single printk for jbd_debug() 2013-08-09 10:49:00 +02:00
jbd2 jbd2: Fix endian mixing problems in the checksumming code 2013-08-28 14:59:58 -04:00
jffs2 [readdir] convert jffs2 2013-06-29 12:56:47 +04:00
jfs jfs: fix readdir cookie incompatibility with NFSv4 2013-08-15 17:22:29 -05:00
lockd LOCKD: Don't call utsname()->nodename from nlmclnt_setlockargs 2013-08-05 15:03:46 -04:00
logfs Lots of bug fixes, cleanups and optimizations. In the bug fixes 2013-07-02 09:39:34 -07:00
minix minix: bug widening a binary "not" operation 2013-06-29 12:57:35 +04:00
ncpfs ncpfs: fix error return code in ncp_parse_options() 2013-07-09 10:33:25 -07:00
nfs nfs: use check_submounts_and_drop() 2013-09-05 16:23:52 -04:00
nfs_common
nfsd nfsd: racy access to ->d_name in nsfd4_encode_path() 2013-09-03 22:50:28 -04:00
nilfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-09-05 08:50:26 -07:00
nls
notify fsnotify: update comments concerning locking scheme 2013-07-09 10:33:20 -07:00
ntfs Lots of bug fixes, cleanups and optimizations. In the bug fixes 2013-07-02 09:39:34 -07:00
ocfs2 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2013-09-07 14:34:07 -07:00
omfs [readdir] convert omfs 2013-06-29 12:56:37 +04:00
openpromfs [readdir] convert openpromfs 2013-06-29 12:56:32 +04:00
proc Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2013-09-07 14:35:32 -07:00
pstore pstore/ram: (really) fix undefined usage of rounddown_pow_of_two 2013-08-30 15:57:01 -07:00
qnx4 [readdir] convert qnx4 2013-06-29 12:56:38 +04:00
qnx6 [readdir] convert qnx6 2013-06-29 12:56:39 +04:00
quota quota: provide interface for readding allocated space into reserved space 2013-08-17 09:32:32 -04:00
ramfs
reiserfs Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2013-09-06 09:06:02 -07:00
romfs [readdir] convert romfs 2013-06-29 12:56:29 +04:00
squashfs [readdir] convert squashfs 2013-06-29 12:56:28 +04:00
sysfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-09-07 14:36:57 -07:00
sysv Don't pass inode to ->d_hash() and ->d_compare() 2013-06-29 12:57:36 +04:00
ubifs Only a single patch which fixes a message. 2013-07-05 12:08:47 -07:00
udf udf: Refuse RW mount of the filesystem instead of making it RO 2013-07-31 22:14:51 +02:00
ufs [readdir] simple local unixlike: switch to ->iterate() 2013-06-29 12:46:47 +04:00
xfs direct-io: Implement generic deferred AIO completions 2013-09-04 09:23:46 -04:00
aio.c aio: fix wrong comment in aio_complete() 2013-07-03 16:08:06 -07:00
anon_inodes.c
attr.c
bad_inode.c [readdir] ->readdir() is gone 2013-06-29 12:57:04 +04:00
binfmt_aout.c mm: remove free_area_cache 2013-07-10 18:11:34 -07:00
binfmt_elf_fdpic.c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc 2013-05-02 10:16:16 -07:00
binfmt_elf.c mm: remove free_area_cache 2013-07-10 18:11:34 -07:00
binfmt_em86.c
binfmt_flat.c new helper: read_code() 2013-04-29 15:40:23 -04:00
binfmt_misc.c binfmt_misc: reuse string_unescape_inplace() 2013-04-30 17:04:03 -07:00
binfmt_script.c
binfmt_som.c
bio-integrity.c
bio.c Merge branch 'for-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2013-09-03 18:25:03 -07:00
block_dev.c direct-io: Handle O_(D)SYNC AIO 2013-09-04 09:23:46 -04:00
buffer.c mm: vmscan: take page buffers dirty and locked state into account 2013-07-03 16:07:29 -07:00
char_dev.c
compat_binfmt_elf.c
compat_ioctl.c compat.c: LOOP_CLR_FD is taken care of in loop.c itself... 2013-06-29 12:46:44 +04:00
compat.c [readdir] constify ->actor 2013-06-29 12:57:05 +04:00
coredump.c coredump: '% at the end' shouldn't bypass core_uses_pid logic 2013-07-03 16:08:02 -07:00
coredump.h
dcache.c vfs: reorganize dput() memory accesses 2013-09-08 13:26:18 -07:00
dcookies.c
direct-io.c direct-io: Handle O_(D)SYNC AIO 2013-09-04 09:23:46 -04:00
drop_caches.c
eventfd.c
eventpoll.c switch epoll_ctl() to fdget 2013-09-03 23:04:44 -04:00
exec.c Fix TLB gather virtual address range invalidation corner cases 2013-08-16 08:52:46 -07:00
fcntl.c vfs: add missing check for __O_TMPFILE in fcntl_init() 2013-08-05 18:25:32 +04:00
fhandle.c
file_table.c only regular files with FMODE_WRITE need to be on s_files 2013-09-03 22:50:28 -04:00
file.c don't bother with deferred freeing of fdtables 2013-05-01 17:31:42 -04:00
filesystems.c
fs_struct.c
fs-writeback.c mm/writeback: don't check force_wait to handle bdi->work_list 2013-07-09 10:33:22 -07:00
generic_acl.c
inode.c constify touch_atime() 2013-09-03 22:52:45 -04:00
internal.h vfs: check unlinked ancestors before mount 2013-09-05 16:23:50 -04:00
ioctl.c
ioprio.c
Kconfig efivarfs: Move to fs/efivarfs 2013-04-17 13:25:09 +01:00
Kconfig.binfmt fs: make binfmt support for #! scripts modular and removable 2013-04-30 17:04:04 -07:00
libfs.c make simple_lookup() usable for filesystems that set ->s_d_op 2013-07-14 17:43:25 +04:00
locks.c locks: move file_lock_list to a set of percpu hlist_heads and convert file_lock_lock to an lglock 2013-07-08 13:36:42 +04:00
Makefile Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-05-01 17:51:54 -07:00
mbcache.c
mount.h get rid of full-hash scan on detaching vfsmounts 2013-04-09 14:12:52 -04:00
mpage.c
namei.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-09-05 08:50:26 -07:00
namespace.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-09-07 14:36:57 -07:00
no-block.c
open.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2013-09-07 14:35:32 -07:00
pipe.c aio: don't include aio.h in sched.h 2013-05-07 20:16:25 -07:00
pnode.c vfs: Fix invalid ida_remove() call 2013-05-31 15:16:33 -04:00
pnode.h vfs: Don't copy mount bind mounts of /proc/<pid>/ns/mnt between namespaces 2013-08-26 18:42:15 -07:00
posix_acl.c
proc_namespace.c
read_write.c vfs: export lseek_execute() to modules 2013-07-03 16:23:27 +04:00
readdir.c [readdir] constify ->actor 2013-06-29 12:57:05 +04:00
select.c net: rename include/net/ll_poll.h to include/net/busy_poll.h 2013-07-10 17:08:27 -07:00
seq_file.c seq_file: add seq_list_*_percpu helpers 2013-07-08 13:36:41 +04:00
signalfd.c
splice.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-07-03 09:10:19 -07:00
stack.c
stat.c quota: provide interface for readding allocated space into reserved space 2013-08-17 09:32:32 -04:00
statfs.c
super.c direct-io: Implement generic deferred AIO completions 2013-09-04 09:23:46 -04:00
sync.c
timerfd.c timerfd: Add alarm timers 2013-05-29 12:57:34 -07:00
utimes.c
xattr_acl.c
xattr.c