WSL2-Linux-Kernel/fs
npiggin@suse.de d3ef3d7351 fs: mnt_want_write speedup
This patch speeds up lmbench lat_mmap test by about 8%. lat_mmap is set up
basically to mmap a 64MB file on tmpfs, fault in its pages, then unmap it.
A microbenchmark yes, but it exercises some important paths in the mm.

Before:
 avg = 501.9
 std = 14.7773

After:
 avg = 462.286
 std = 5.46106

(50 runs of each, stddev gives a reasonable confidence, but there is quite
a bit of variation there still)

It does this by removing the complex per-cpu locking and counter-cache and
replaces it with a percpu counter in struct vfsmount. This makes the code
much simpler, and avoids spinlocks (although the msync is still pretty
costly, unfortunately). It results in about 900 bytes smaller code too. It
does increase the size of a vfsmount, however.

It should also give a speedup on large systems if CPUs are frequently operating
on different mounts (because the existing scheme has to operate on an atomic in
the struct vfsmount when switching between mounts). But I'm most interested in
the single threaded path performance for the moment.

[AV: minor cleanup]

Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:02 -04:00
..
9p Fix a leak in failure exit in 9p ->get_sb() 2009-05-09 10:49:40 -04:00
adfs fs/adfs: return f_fsid for statfs(2) 2009-04-02 19:05:08 -07:00
affs Fix races around the access to ->s_options 2009-05-09 10:51:34 -04:00
afs switch follow_down() 2009-06-11 21:36:01 -04:00
autofs switch follow_down() 2009-06-11 21:36:01 -04:00
autofs4 switch follow_down() 2009-06-11 21:36:01 -04:00
befs befs: fix build on parisc 2009-04-08 10:21:43 -07:00
bfs fs/Kconfig: move bfs out 2009-01-22 13:15:57 +03:00
btrfs Btrfs: fix extent_buffer leak during tree log replay 2009-06-11 11:24:47 -04:00
cachefiles CacheFiles: Fixup renamed filenames in comments in internal.h 2009-05-27 10:20:13 -07:00
cifs switch follow_down() 2009-06-11 21:36:01 -04:00
coda splice: implement default splice_read method 2009-05-11 14:13:10 +02:00
configfs configfs: Fix Trivial Warning in fs/configfs/symlink.c 2009-04-21 12:59:21 -07:00
cramfs fs/cramfs: return f_fsid for statfs(2) 2009-04-02 19:05:08 -07:00
debugfs debugfs: function to know if debugfs is initialized 2009-03-23 16:25:46 +01:00
devpts devpts: unregister the file system on error 2009-06-11 08:51:06 -07:00
dlm dlm: fix length calculation in compat code 2009-03-11 12:23:59 -05:00
ecryptfs Convert obvious places to deactivate_locked_super() 2009-05-09 10:49:40 -04:00
efs fs/efs: return f_fsid for statfs(2) 2009-04-02 19:05:09 -07:00
exofs block: add rq->resid_len 2009-05-11 09:50:53 +02:00
exportfs
ext2 ext2: Fix memory leak in ext2_fill_super() in case of a failed mount 2009-05-17 23:52:51 -04:00
ext3 Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block 2009-06-11 11:10:35 -07:00
ext4 Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block 2009-06-11 11:10:35 -07:00
fat vfat: Note the NLS requirement 2009-04-17 09:32:11 -07:00
freevxfs fs/Kconfig: move vxfs out 2009-01-22 13:15:58 +03:00
fscache FS-Cache: Fixup renamed filenames in comments in internal.h 2009-05-27 10:20:13 -07:00
fuse Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse 2009-05-13 16:32:57 -07:00
gfs2 Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block 2009-06-11 11:10:35 -07:00
hfs hfs: fix memory leak when unmounting 2009-04-13 15:04:29 -07:00
hfsplus Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
hostfs constify dentry_operations: misc filesystems 2009-03-27 14:44:00 -04:00
hpfs Fix races around the access to ->s_options 2009-05-09 10:51:34 -04:00
hppfs hppfs: hppfs_read_file() may return -ERROR 2009-04-02 19:04:53 -07:00
hugetlbfs Merge branch 'master' into next 2009-05-22 18:40:59 +10:00
isofs fs/isofs: return f_fsid for statfs(2) 2009-04-02 19:05:09 -07:00
jbd jbd: fix race in buffer processing in commit code 2009-06-09 16:59:03 -07:00
jbd2 jbd2: Fix minor typos in comments in fs/jbd2/journal.c 2009-06-09 00:06:20 -04:00
jffs2 jffs2: Fix corruption when flash erase/write failure 2009-05-29 10:44:46 +01:00
jfs jfs: Add missing mutex_unlock call to error path 2009-05-23 20:28:41 -05:00
lockd lockd: fix list corruption on lockd restart 2009-05-06 17:19:36 -04:00
minix fs/minix: return f_fsid for statfs(2) 2009-04-02 19:05:09 -07:00
ncpfs ncpfs: use memdup_user() 2009-04-20 23:02:51 -04:00
nfs switch follow_down() 2009-06-11 21:36:01 -04:00
nfs_common
nfsd switch follow_down() 2009-06-11 21:36:01 -04:00
nilfs2 Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block 2009-06-11 11:10:35 -07:00
nls
notify fsnotify: allow groups to set freeing_mark to null 2009-06-11 14:57:55 -04:00
ntfs block: Do away with the notion of hardsect_size 2009-05-22 23:22:54 +02:00
ocfs2 block: Do away with the notion of hardsect_size 2009-05-22 23:22:54 +02:00
omfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2009-04-02 21:09:10 -07:00
openpromfs
partitions block: Export I/O topology for block devices and partitions 2009-05-22 23:22:55 +02:00
proc Move junk from proc_fs.h to fs/proc/internal.h 2009-06-11 21:36:01 -04:00
qnx4 fs/qnx4: return f_fsid for statfs(2) 2009-04-02 19:05:10 -07:00
quota quota: remove obsolete comments in fs/quota/Makefile 2009-04-27 16:49:52 +02:00
ramfs ramfs: fix double freeing s_fs_info on failed mount 2009-04-07 07:39:59 -07:00
reiserfs reiserfs: allow exposing privroot w/ xattrs enabled 2009-06-11 21:35:58 -04:00
romfs ROMFS: romfs_dev_read() error ignored 2009-05-09 10:49:41 -04:00
smbfs constify dentry_operations: misc filesystems 2009-03-27 14:44:00 -04:00
squashfs Squashfs: cody tidying, remove commented out line in Makefile 2009-05-13 03:25:20 +01:00
sysfs sysfs: file.c: use create_singlethread_workqueue() 2009-05-28 14:24:07 -07:00
sysv fs/sysv: return f_fsid for statfs(2) 2009-04-02 19:05:10 -07:00
ubifs Convert obvious places to deactivate_locked_super() 2009-05-09 10:49:40 -04:00
udf block: Do away with the notion of hardsect_size 2009-05-22 23:22:54 +02:00
ufs switch ufs directories to ufs_sync_file() 2009-05-09 10:49:42 -04:00
xfs Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block 2009-06-11 11:10:35 -07:00
Kconfig nilfs2: update makefile and Kconfig 2009-04-07 08:31:16 -07:00
Kconfig.binfmt CORE_DUMP_DEFAULT_ELF_HEADERS depends on ELF_CORE 2009-01-09 16:54:41 -08:00
Makefile nilfs2: update makefile and Kconfig 2009-04-07 08:31:16 -07:00
aio.c aio: lookup_ioctx can return the wrong value when looking up a bogus context 2009-03-19 15:57:18 -07:00
anon_inodes.c constify dentry_operations: rest 2009-03-27 14:44:03 -04:00
attr.c vfs: Use lowercase names of quota functions 2009-03-26 02:18:35 +01:00
bad_inode.c
binfmt_aout.c
binfmt_elf.c Trim includes in binfmt_elf 2009-03-31 23:00:27 -04:00
binfmt_elf_fdpic.c ptrace: s/parent/real_parent/ in binfmt_elf_fdpic.c 2009-05-02 15:36:10 -07:00
binfmt_em86.c
binfmt_flat.c flat: fix data sections alignment 2009-05-29 08:40:02 -07:00
binfmt_misc.c fs/binfmt_misc.c: add terminating newline to /proc/sys/fs/binfmt_misc/status 2009-01-06 15:59:19 -08:00
binfmt_script.c
binfmt_som.c Don't crap into descriptor table in binfmt_som 2009-03-31 23:00:28 -04:00
bio-integrity.c block: add private bio_set for bio integrity allocations 2009-03-24 12:35:17 +01:00
bio.c Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block 2009-06-11 11:10:35 -07:00
block_dev.c Merge branch 'for-linus' of git://linux-arm.org/linux-2.6 2009-06-11 14:15:57 -07:00
buffer.c Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block 2009-06-11 11:10:35 -07:00
char_dev.c fs: fix name overwrite in __register_chrdev_region() 2009-01-06 15:59:13 -08:00
compat.c CRED: Rename cred_exec_mutex to reflect that it's a guard against ptrace 2009-05-11 08:15:36 +10:00
compat_binfmt_elf.c
compat_ioctl.c fs/compat_ioctl: fix build when !BLOCK 2009-04-20 23:01:16 -04:00
dcache.c fs: dcache fix LRU ordering 2009-05-09 10:49:40 -04:00
dcookies.c [CVE-2009-0029] System call wrapper special cases 2009-01-14 14:15:18 +01:00
direct-io.c block: Do away with the notion of hardsect_size 2009-05-22 23:22:54 +02:00
drop_caches.c vfs: skip I_CLEAR state inodes 2009-04-02 19:04:48 -07:00
eventfd.c epoll keyed wakeups: make eventfd use keyed wakeups 2009-04-01 08:59:20 -07:00
eventpoll.c epoll: fix size check in epoll_create() 2009-05-12 14:11:35 -07:00
exec.c Merge branch 'perfcounters-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-06-11 14:01:07 -07:00
fcntl.c dup2: Fix return value with oldfd == newfd and invalid fd 2009-05-11 12:18:06 -07:00
fifo.c
file.c
file_table.c trivial: remove unused variable 'path' in alloc_file() 2009-03-30 15:22:03 +02:00
filesystems.c fs: Mark get_filesystem_list() as __init function. 2009-04-20 23:02:52 -04:00
fs-writeback.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2009-04-03 15:24:35 -07:00
fs_struct.c Get rid of indirect include of fs_struct.h 2009-03-31 23:00:27 -04:00
generic_acl.c New helper - current_umask() 2009-03-31 23:00:26 -04:00
inode.c fsnotify: handle filesystem unmounts with fsnotify marks 2009-06-11 14:57:54 -04:00
internal.h New locking/refcounting for fs_struct 2009-03-31 23:00:26 -04:00
ioctl.c fiemap: fix problem with setting FIEMAP_EXTENT_LAST 2009-05-06 16:36:09 -07:00
ioprio.c [CVE-2009-0029] System call wrappers part 28 2009-01-14 14:15:30 +01:00
libfs.c Convert obvious places to deactivate_locked_super() 2009-05-09 10:49:40 -04:00
locks.c [CVE-2009-0029] System call wrappers part 16 2009-01-14 14:15:25 +01:00
mbcache.c
mpage.c ext4: Properly initialize the buffer_head state 2009-05-13 15:13:42 -04:00
namei.c switch lookup_mnt() 2009-06-11 21:36:01 -04:00
namespace.c fs: mnt_want_write speedup 2009-06-11 21:36:02 -04:00
nfsctl.c [CVE-2009-0029] System call wrappers part 27 2009-01-14 14:15:29 +01:00
no-block.c
open.c Switch open_exec() and sys_uselib() to do_open_filp() 2009-05-09 10:49:42 -04:00
pipe.c splice: implement default splice_read method 2009-05-11 14:13:10 +02:00
pnode.c
pnode.h
posix_acl.c
read_write.c splice: implement default splice_read method 2009-05-11 14:13:10 +02:00
read_write.h
readdir.c [CVE-2009-0029] System call wrappers part 32 2009-01-14 14:15:31 +01:00
select.c [CVE-2009-0029] System call wrappers part 32 2009-01-14 14:15:31 +01:00
seq_file.c cpumask: fix seq_bitmap_*() functions. 2009-03-30 22:05:11 +10:30
signalfd.c [CVE-2009-0029] System call wrappers part 31 2009-01-14 14:15:31 +01:00
splice.c splice: fix kmaps in default_file_splice_write() 2009-05-19 11:37:46 +02:00
stack.c
stat.c kill vfs_stat_fd / vfs_lstat_fd 2009-04-20 23:02:52 -04:00
super.c NULL noise in fs/super.c:kill_bdev_super() 2009-05-09 10:49:41 -04:00
sync.c Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-quota-2.6 2009-03-27 14:48:34 -07:00
timerfd.c timerfd: add flags check 2009-02-18 15:37:53 -08:00
utimes.c [CVE-2009-0029] System call wrappers part 30 2009-01-14 14:15:30 +01:00
xattr.c xattr: use memdup_user() 2009-04-20 23:02:50 -04:00
xattr_acl.c