kernel-ark/fs
Dipankar Sarma 529bf6be5c [PATCH] fix file counting
I have benchmarked this on an x86_64 NUMA system and see no significant
performance difference on kernbench.  Tested on both x86_64 and powerpc.

The way we do file struct accounting is not very suitable for batched
freeing.  For scalability reasons, file accounting was
constructor/destructor based.  This meant that nr_files was decremented
only when the object was removed from the slab cache.  This is susceptible
to slab fragmentation.  With RCU based file structure, consequent batched
freeing and a test program like Serge's, we just speed this up and end up
with a very fragmented slab -

llm22:~ # cat /proc/sys/fs/file-nr
587730  0       758844

At the same time, I see only a 2000+ objects in filp cache.  The following
patch I fixes this problem.

This patch changes the file counting by removing the filp_count_lock.
Instead we use a separate percpu counter, nr_files, for now and all
accesses to it are through get_nr_files() api.  In the sysctl handler for
nr_files, we populate files_stat.nr_files before returning to user.

Counting files as an when they are created and destroyed (as opposed to
inside slab) allows us to correctly count open files with RCU.

Signed-off-by: Dipankar Sarma <dipankar@in.ibm.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-08 14:14:01 -08:00
..
9p
adfs
affs
afs
autofs
autofs4
befs
bfs
cifs
coda
configfs
cramfs
debugfs
devfs
devpts
efs
exportfs
ext2
ext3
fat
freevxfs
fuse
hfs
hfsplus
hostfs
hpfs
hppfs
hugetlbfs
isofs
jbd
jffs
jffs2
jfs
lockd
minix
msdos
ncpfs
nfs
nfs_common
nfsd
nls
ntfs
ocfs2
openpromfs
partitions
proc [PATCH] smaps: shared fix 2006-03-06 18:40:45 -08:00
qnx4
ramfs
reiserfs
relayfs
romfs
smbfs
sysfs
sysv
udf [PATCH] udf: fix uid/gid options and add uid/gid=ignore and forget options 2006-03-08 14:14:00 -08:00
ufs
vfat
xfs
aio.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf_fdpic.c
binfmt_elf.c
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
binfmt_som.c
bio.c
block_dev.c
buffer.c
char_dev.c
compat_ioctl.c
compat.c
dcache.c [PATCH] fix file counting 2006-03-08 14:14:01 -08:00
dcookies.c
direct-io.c
dnotify.c
dquot.c
drop_caches.c
eventpoll.c
exec.c
fcntl.c
fifo.c Simplify fifo_open() locking logic 2006-03-07 09:16:35 -08:00
file_table.c [PATCH] fix file counting 2006-03-08 14:14:01 -08:00
file.c
filesystems.c
fs-writeback.c
inode.c
inotify.c
ioctl.c
ioprio.c
Kconfig
Kconfig.binfmt
libfs.c
locks.c
Makefile
mbcache.c
mpage.c
namei.c
namespace.c
nfsctl.c
open.c
pipe.c Mark the pipe file operations static 2006-03-08 14:03:09 -08:00
pnode.c
pnode.h
posix_acl.c
quota_v1.c
quota_v2.c
quota.c
read_write.c
readdir.c
select.c
seq_file.c
stat.c
super.c
xattr_acl.c
xattr.c