Star64_linux/fs
Dave Chinner c76febef57 xfs: only run xfs_error_test if error injection is active
Recent tests writing lots of small files showed the flusher thread
being CPU bound and taking a long time to do allocations on a debug
kernel. perf showed this as the prime reason:

             samples  pcnt function                    DSO
             _______ _____ ___________________________ _________________

           224648.00 36.8% xfs_error_test              [kernel.kallsyms]
            86045.00 14.1% xfs_btree_check_sblock      [kernel.kallsyms]
            39778.00  6.5% prandom32                   [kernel.kallsyms]
            37436.00  6.1% xfs_btree_increment         [kernel.kallsyms]
            29278.00  4.8% xfs_btree_get_rec           [kernel.kallsyms]
            27717.00  4.5% random32                    [kernel.kallsyms]

Walking btree blocks during allocation checking them requires each
block (a cache hit, so no I/O) call xfs_error_test(), which then
does a random32() call as the first operation.  IOWs, ~50% of the
CPU is being consumed just testing whether we need to inject an
error, even though error injection is not active.

Kill this overhead when error injection is not active by adding a
global counter of active error traps and only calling into
xfs_error_test when fault injection is active.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-01 07:40:20 -06:00
..
9p
adfs
affs
afs
autofs4
befs
bfs
btrfs Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable 2010-11-29 14:11:08 -08:00
cachefiles
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2010-11-19 15:32:22 -08:00
cifs
coda
configfs
cramfs
debugfs
devpts
dlm
ecryptfs BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
efs
exofs
exportfs
ext2
ext3 BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
ext4 ext4: Add EXT4_IOC_TRIM ioctl to handle batched discard 2010-11-19 21:47:07 -05:00
fat
freevxfs
fscache
fuse fuse: fix attributes after open(O_TRUNC) 2010-11-25 06:50:41 +09:00
gfs2 GFS2: Userland expects quota limit/warn/usage in 512b blocks 2010-11-19 11:20:29 +00:00
hfs
hfsplus
hostfs
hpfs
hppfs
hugetlbfs
isofs
jbd
jbd2 jbd2: fix /proc/fs/jbd2/<dev> when using an external journal 2010-11-17 21:46:26 -05:00
jffs2
jfs
lockd BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
logfs
minix
ncpfs BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
nfs NFS: Ensure we return the dirent->d_type when it is known 2010-11-22 13:24:48 -05:00
nfs_common
nfsd BKL: remove references to lock_kernel from comments 2010-11-17 08:59:32 -08:00
nilfs2 nilfs2: fix typo in comment of nilfs_dat_move function 2010-11-24 12:51:48 +09:00
nls
notify
ntfs
ocfs2 BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
omfs
openpromfs
partitions
proc pagemap: set pagemap walk limit to PMD boundary 2010-11-25 06:50:46 +09:00
qnx4
quota
ramfs
reiserfs reiserfs: fix inode mutex - reiserfs lock misordering 2010-11-25 06:50:48 +09:00
romfs
squashfs
sysfs
sysv
ubifs
udf
ufs
xfs xfs: only run xfs_error_test if error injection is active 2010-12-01 07:40:20 -06:00
aio.c
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf.c
binfmt_elf_fdpic.c
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
binfmt_som.c
bio-integrity.c
bio.c
block_dev.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
buffer.c
char_dev.c
compat.c
compat_binfmt_elf.c
compat_ioctl.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
dcache.c
dcookies.c
direct-io.c
drop_caches.c
eventfd.c
eventpoll.c
exec.c
fcntl.c
fifo.c
file.c
file_table.c
filesystems.c
fs-writeback.c
fs_struct.c
generic_acl.c
inode.c
internal.h
ioctl.c Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 2010-11-19 19:46:45 -08:00
ioprio.c ioprio: grab rcu_read_lock in sys_ioprio_{set,get}() 2010-11-15 10:23:31 +01:00
Kconfig
Kconfig.binfmt
libfs.c
locks.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
Makefile
mbcache.c
mpage.c
namei.c
namespace.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
nfsctl.c
no-block.c
open.c
pipe.c Un-inline get_pipe_info() helper function 2010-11-28 16:27:19 -08:00
pnode.c
pnode.h
posix_acl.c
read_write.c BKL: remove extraneous #include <smp_lock.h> 2010-11-17 08:59:32 -08:00
read_write.h
readdir.c
select.c
seq_file.c
signalfd.c
splice.c Export 'get_pipe_info()' to other users 2010-11-28 14:09:57 -08:00
stack.c
stat.c
statfs.c
super.c
sync.c
timerfd.c
utimes.c
xattr.c
xattr_acl.c