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9bc08a45fb
linux-kernel-test/fs
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Dave Chinner 9bc08a45fb xfs: improve buffer cache hash scalability 
When doing large parallel file creates on a 16p machines, large amounts of
time is being spent in _xfs_buf_find(). A system wide profile with perf top
shows this:

          1134740.00 19.3% _xfs_buf_find
           733142.00 12.5% __ticket_spin_lock

The problem is that the hash contains 45,000 buffers, and the hash table width
is only 256 buffers. That means we've got around 200 buffers per chain, and
searching it is quite expensive. The hash table size needs to increase.

Secondly, every time we do a lookup, we promote the buffer we find to the head
of the hash chain. This is causing cachelines to be dirtied and causes
invalidation of cachelines across all CPUs that may have walked the hash chain
recently. hence every walk of the hash chain is effectively a cold cache walk.
Remove the promotion to avoid this invalidation.

The results are:

          1045043.00 21.2% __ticket_spin_lock
           326184.00  6.6% _xfs_buf_find

A 70% drop in the CPU usage when looking up buffers. Unfortunately that does
not result in an increase in performance underthis workload as contention on
the inode_lock soaks up most of the reduction in CPU usage.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-09-02 15:14:38 +10:00
..
9p v9fs: fixup for inode_setattr being removed 2010-08-11 00:08:00 -04:00
adfs check ATTR_SIZE contraints in inode_change_ok 2010-08-09 16:47:39 -04:00
affs AFFS: wait for sb synchronization when needed 2010-08-09 16:48:51 -04:00
afs Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6 2010-08-13 10:37:30 -07:00
autofs autofs/autofs4: Move compat_ioctl handling into fs 2010-08-09 00:13:34 +02:00
autofs4 autofs4: remove unneeded null check in try_to_fill_dentry() 2010-08-11 08:59:06 -07:00
befs
bfs BFS: clean up the superblock usage 2010-08-09 16:48:53 -04:00
btrfs Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block 2010-08-10 15:22:42 -07:00
cachefiles Add a dummy printk function for the maintenance of unused printks 2010-08-12 09:51:35 -07:00
ceph ceph: fix get_ticket_handler() error handling 2010-08-26 09:26:50 -07:00
cifs Cannot allocate memory error on mount 2010-08-26 16:53:27 +00:00
coda Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block 2010-08-10 15:22:42 -07:00
configfs
cramfs cramfs: only unlock new inodes 2010-08-18 01:01:33 -04:00
debugfs
devpts
dlm fs/dlm: Drop unnecessary null test 2010-08-05 14:23:45 -05:00
ecryptfs eCryptfs: Fix encrypted file name lookup regression 2010-08-27 10:50:53 -05:00
efs
exofs Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osd 2010-08-11 09:19:43 -07:00
exportfs
ext2 mbcache: Remove unused features 2010-08-09 16:48:45 -04:00
ext3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
ext4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
fat remove SWRITE* I/O types 2010-08-18 01:09:01 -04:00
freevxfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
fscache Add a dummy printk function for the maintenance of unused printks 2010-08-12 09:51:35 -07:00
fuse Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
gfs2 Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block 2010-08-10 15:22:42 -07:00
hfs convert remaining ->clear_inode() to ->evict_inode() 2010-08-09 16:48:37 -04:00
hfsplus convert remaining ->clear_inode() to ->evict_inode() 2010-08-09 16:48:37 -04:00
hostfs hostfs ->follow_link() braino 2010-08-18 06:21:10 -04:00
hpfs switch hpfs to ->evict_inode() 2010-08-09 16:48:17 -04:00
hppfs switch hppfs to ->evict_inode() 2010-08-09 16:48:16 -04:00
hugetlbfs new helper: end_writeback() 2010-08-09 16:47:49 -04:00
isofs isofs: Fix lseek() to position beyond 4 GB 2010-08-11 00:29:47 -04:00
jbd remove SWRITE* I/O types 2010-08-18 01:09:01 -04:00
jbd2 remove SWRITE* I/O types 2010-08-18 01:09:01 -04:00
jffs2 Merge git://git.infradead.org/mtd-2.6 2010-08-10 11:49:21 -07:00
jfs jfs: don't allow os2 xattr namespace overlap with others 2010-08-10 15:33:09 -07:00
lockd
logfs logfs: kill BKL 2010-08-14 00:24:24 +02:00
minix switch minix to ->evict_inode(), fix write_inode/delete_inode race 2010-08-09 16:47:53 -04:00
ncpfs Merge branch 'bkl/ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing 2010-08-10 13:58:28 -07:00
nfs Merge branch 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6 2010-08-18 15:45:23 -07:00
nfs_common
nfsd Merge branch 'for-2.6.36' of git://linux-nfs.org/~bfields/linux 2010-08-28 14:05:55 -07:00
nilfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2 2010-08-22 09:44:47 -07:00
nls
notify fsnotify: drop two useless bools in the fnsotify main loop 2010-08-27 21:42:11 -04:00
ntfs convert remaining ->clear_inode() to ->evict_inode() 2010-08-09 16:48:37 -04:00
ocfs2 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2 2010-08-13 10:43:50 -07:00
omfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bcopeland/omfs 2010-08-10 11:47:36 -07:00
openpromfs
partitions [S390] partitions: fix build error in ibm partition detection code 2010-08-13 10:06:55 +02:00
proc mm: fix up some user-visible effects of the stack guard page 2010-08-15 11:35:52 -07:00
qnx4 get rid of cont_write_begin_newtrunc 2010-08-09 16:47:31 -04:00
quota Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
ramfs check ATTR_SIZE contraints in inode_change_ok 2010-08-09 16:47:39 -04:00
reiserfs remove SWRITE* I/O types 2010-08-18 01:09:01 -04:00
romfs
smbfs switch smbfs to evict_inode() 2010-08-09 16:48:00 -04:00
squashfs Squashfs: fix checkpatch.pl warnings 2010-08-08 22:29:33 +00:00
sysfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
sysv fs/sysv/super.c: add support for non-PDP11 v7 filesystems 2010-08-11 08:59:23 -07:00
ubifs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
udf Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
ufs remove SWRITE* I/O types 2010-08-18 01:09:01 -04:00
xfs xfs: improve buffer cache hash scalability 2010-09-02 15:14:38 +10:00
aio.c aio: fix wrong subsystem comments 2010-08-05 13:21:23 -07:00
anon_inodes.c
attr.c check ATTR_SIZE contraints in inode_change_ok 2010-08-09 16:47:39 -04:00
bad_inode.c bkl: Remove locked .ioctl file operation 2010-08-14 00:24:24 +02:00
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
binfmt_script.c Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
binfmt_som.c
bio-integrity.c
bio.c block: unify flags for struct bio and struct request 2010-08-07 18:20:39 +02:00
block_dev.c blkdev: cgroup whitelist permission fix 2010-08-11 08:59:18 -07:00
buffer.c remove SWRITE* I/O types 2010-08-18 01:09:01 -04:00
char_dev.c Fix init ordering of /dev/console vs callers of modprobe 2010-08-06 09:17:02 -07:00
compat_binfmt_elf.c
compat_ioctl.c bkl: Remove locked .ioctl file operation 2010-08-14 00:24:24 +02:00
compat.c Mark arguments to certain syscalls as being const 2010-08-13 16:53:13 -07:00
dcache.c fs: brlock vfsmount_lock 2010-08-18 08:35:48 -04:00
dcookies.c
direct-io.c sort out blockdev_direct_IO variants 2010-08-09 16:47:29 -04:00
drop_caches.c simplify checks for I_CLEAR/I_FREEING 2010-08-09 16:47:44 -04:00
eventfd.c
eventpoll.c
exec.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-18 09:35:08 -07:00
fcntl.c vfs: O_* bit numbers uniqueness check 2010-08-11 08:59:02 -07:00
fifo.c
file_table.c fs: scale files_lock 2010-08-18 08:35:48 -04:00
file.c vfs: use kmalloc() to allocate fdmem if possible 2010-08-11 08:59:02 -07:00
filesystems.c
fs_struct.c fs: fs_struct rwlock to spinlock 2010-08-18 08:35:46 -04:00
fs-writeback.c mm: fix writeback_in_progress() 2010-08-12 08:43:30 -07:00
generic_acl.c vfs: update ctime when changing the file's permission by setfacl 2010-08-18 01:04:22 -04:00
inode.c Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify 2010-08-10 11:39:13 -07:00
internal.h fs: brlock vfsmount_lock 2010-08-18 08:35:48 -04:00
ioctl.c bkl: Remove locked .ioctl file operation 2010-08-14 00:24:24 +02:00
ioprio.c
Kconfig
Kconfig.binfmt
libfs.c check ATTR_SIZE contraints in inode_change_ok 2010-08-09 16:47:39 -04:00
locks.c
Makefile
mbcache.c mbcache: Limit the maximum number of cache entries 2010-08-18 06:24:41 -04:00
mpage.c
namei.c fs: brlock vfsmount_lock 2010-08-18 08:35:48 -04:00
namespace.c fs: brlock vfsmount_lock 2010-08-18 08:35:48 -04:00
nfsctl.c
no-block.c
open.c fs: cleanup files_lock locking 2010-08-18 08:35:47 -04:00
pipe.c
pnode.c fs: brlock vfsmount_lock 2010-08-18 08:35:48 -04:00
pnode.h
posix_acl.c
read_write.c fsnotify: pass a file instead of an inode to open, read, and write 2010-07-28 09:58:32 -04:00
read_write.h
readdir.c vfs: fix warning: 'dirent' is used uninitialized in this function 2010-08-09 20:45:05 -07:00
select.c
seq_file.c
signalfd.c signalfd: fill in ssi_int for posix timers and message queues 2010-08-11 08:59:20 -07:00
splice.c splice: fix misuse of SPLICE_F_NONBLOCK 2010-08-07 18:52:56 +02:00
stack.c
stat.c Mark arguments to certain syscalls as being const 2010-08-13 16:53:13 -07:00
statfs.c add f_flags to struct statfs(64) 2010-08-09 16:48:44 -04:00
super.c fs: scale files_lock 2010-08-18 08:35:48 -04:00
sync.c get rid of file_fsync() 2010-08-09 16:47:43 -04:00
timerfd.c
utimes.c Mark arguments to certain syscalls as being const 2010-08-13 16:53:13 -07:00
xattr_acl.c
xattr.c