linux/fs
Darrick J. Wong 1d1d1a7672 mm: only enforce stable page writes if the backing device requires it
Create a helper function to check if a backing device requires stable
page writes and, if so, performs the necessary wait.  Then, make it so
that all points in the memory manager that handle making pages writable
use the helper function.  This should provide stable page write support
to most filesystems, while eliminating unnecessary waiting for devices
that don't require the feature.

Before this patchset, all filesystems would block, regardless of whether
or not it was necessary.  ext3 would wait, but still generate occasional
checksum errors.  The network filesystems were left to do their own
thing, so they'd wait too.

After this patchset, all the disk filesystems except ext3 and btrfs will
wait only if the hardware requires it.  ext3 (if necessary) snapshots
pages instead of blocking, and btrfs provides its own bdi so the mm will
never wait.  Network filesystems haven't been touched, so either they
provide their own stable page guarantees or they don't block at all.
The blocking behavior is back to what it was before 3.0 if you don't
have a disk requiring stable page writes.

Here's the result of using dbench to test latency on ext2:

3.8.0-rc3:
 Operation      Count    AvgLat    MaxLat
 ----------------------------------------
 WriteX        109347     0.028    59.817
 ReadX         347180     0.004     3.391
 Flush          15514    29.828   287.283

Throughput 57.429 MB/sec  4 clients  4 procs  max_latency=287.290 ms

3.8.0-rc3 + patches:
 WriteX        105556     0.029     4.273
 ReadX         335004     0.005     4.112
 Flush          14982    30.540   298.634

Throughput 55.4496 MB/sec  4 clients  4 procs  max_latency=298.650 ms

As you can see, the maximum write latency drops considerably with this
patch enabled.  The other filesystems (ext3/ext4/xfs/btrfs) behave
similarly, but see the cover letter for those results.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Acked-by: Steven Whitehouse <swhiteho@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-21 17:22:19 -08:00
..
9p fs/9p: Fix atomic_open 2013-02-10 16:29:59 -06:00
adfs adfs: drop vmtruncate 2012-12-20 14:00:01 -05:00
affs affs: drop vmtruncate 2012-12-20 14:00:01 -05:00
afs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
autofs4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2012-12-17 15:44:47 -08:00
befs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
bfs bfs: drop vmtruncate 2012-12-20 14:00:01 -05:00
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2013-02-08 12:06:46 +11:00
cachefiles FS-Cache: Mark cancellation of in-progress operation 2012-12-20 22:34:00 +00:00
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2012-12-20 14:00:13 -08:00
cifs fs/cifs/cifs_dfs_ref.c: fix potential memory leakage 2013-01-22 23:58:16 -06:00
coda fs: push rcu_barrier() from deactivate_locked_super() to filesystems 2012-10-02 21:35:55 -04:00
configfs configfs: move the dereference below the NULL test 2013-02-21 17:22:19 -08:00
cramfs userns: Convert cramfs to use kuid/kgid where appropriate 2012-09-21 03:13:08 -07:00
debugfs debugfs: convert gid= argument from decimal, not octal 2013-01-11 05:56:01 -08:00
devpts TTY: devpts, document devpts inode operations 2012-10-22 16:50:13 -07:00
dlm dlm for 3.9 2013-02-21 09:25:23 -08:00
ecryptfs fs/ecryptfs/crypto.c: make ecryptfs_encode_for_filename() static 2012-12-18 10:10:13 -06:00
efs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
exofs exofs: don't leak io_state and pages on read error 2012-12-14 12:17:32 +02:00
exportfs Merge branch 'for-3.8' of git://linux-nfs.org/~bfields/linux 2012-12-20 14:04:11 -08:00
ext2 ext2: fix return values on parse_options() failure 2012-10-09 23:23:53 +02:00
ext3 lseek: the "whence" argument is called "whence" 2012-12-17 17:15:12 -08:00
ext4 mm: only enforce stable page writes if the backing device requires it 2013-02-21 17:22:19 -08:00
f2fs f2fs: use _safe() version of list_for_each 2013-01-22 10:49:00 +09:00
fat fat: fix incorrect function comment 2012-12-20 17:40:20 -08:00
freevxfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
fscache FS-Cache: Clear remaining page count on retrieval cancellation 2012-12-20 22:35:15 +00:00
fuse fuse: allow control of adaptive readdirplus use 2013-02-07 14:25:44 +01:00
gfs2 mm: only enforce stable page writes if the backing device requires it 2013-02-21 17:22:19 -08:00
hfs hfs: drop vmtruncate 2012-12-20 14:00:01 -05:00
hfsplus Merge branch 'akpm' (Andrew's patch-bomb) 2012-12-20 20:00:43 -08:00
hostfs Merge branch 'for-linus-37rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2012-10-10 11:15:20 +09:00
hpfs hpfs: drop vmtruncate 2012-12-20 18:40:00 -05:00
hppfs pidns: Use task_active_pid_ns where appropriate 2012-11-19 05:59:09 -08:00
hugetlbfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2012-12-13 12:00:02 -08:00
isofs tmpfs,ceph,gfs2,isofs,reiserfs,xfs: fix fh_len checking 2012-10-09 23:33:55 -04:00
jbd jbd: don't wake kjournald unnecessarily 2013-01-14 22:50:45 +01:00
jbd2 Various bug fixes for ext4. Perhaps the most serious bug fixed is one 2013-01-02 09:57:34 -08:00
jffs2 jffs2: hold erase_completion_lock on exit 2012-11-18 11:59:01 +02:00
jfs jfs: drop vmtruncate 2012-12-20 18:40:52 -05:00
lockd NLM: Ensure that we resend all pending blocking locks after a reclaim 2013-02-19 12:18:27 -05:00
logfs logfs: drop vmtruncate 2012-12-20 18:40:53 -05:00
minix minix: drop vmtruncate 2012-12-20 18:40:53 -05:00
ncpfs ncpfs: drop vmtruncate 2012-12-20 18:40:54 -05:00
nfs umount oops when remove blocklayoutdriver first 2013-02-17 15:40:15 -05:00
nfs_common
nfsd Revert "nfsd: warn on odd reply state in nfsd_vfs_read" 2012-12-21 17:07:45 -08:00
nilfs2 mm: only enforce stable page writes if the backing device requires it 2013-02-21 17:22:19 -08:00
nls
notify inotify: remove broken mask checks causing unmount to be EINVAL 2013-02-21 17:22:16 -08:00
ntfs ntfs: drop vmtruncate 2012-12-20 18:40:55 -05:00
ocfs2 ocfs2: unlock super lock if lockres refresh failed 2013-02-21 17:22:19 -08:00
omfs omfs: drop vmtruncate 2012-12-20 14:00:01 -05:00
openpromfs fs: push rcu_barrier() from deactivate_locked_super() to filesystems 2012-10-02 21:35:55 -04:00
proc Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2013-02-20 18:58:50 -08:00
pstore A few fixes to reduce places where pstore might hang 2013-02-21 09:38:18 -08:00
qnx4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
qnx6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
quota quota: Use the pre-processor to compile out quotactl_cmd_write when !CONFIG_BLOCK 2012-12-13 16:33:24 +01:00
ramfs
reiserfs reiserfs: drop vmtruncate 2012-12-20 14:00:01 -05:00
romfs fs: push rcu_barrier() from deactivate_locked_super() to filesystems 2012-10-02 21:35:55 -04:00
squashfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-10-02 20:25:04 -07:00
sysfs sysfs: Functions for adding/removing symlinks to/from attribute groups 2013-01-25 21:51:13 +01:00
sysv sysv: drop vmtruncate 2012-12-20 14:00:01 -05:00
ubifs ubifs: use prandom_bytes 2012-12-17 17:15:26 -08:00
udf UDF: Fix a null pointer dereference in udf_sb_free_partitions 2013-01-14 22:53:47 +01:00
ufs ufs: drop vmtruncate 2012-12-20 14:00:01 -05:00
xfs xfs: xfs_bmap_add_attrfork_local is too generic 2013-02-14 17:35:51 -06:00
aio.c
anon_inodes.c
attr.c userns: Allow chown and setgid preservation 2012-11-20 04:17:24 -08:00
bad_inode.c lseek: the "whence" argument is called "whence" 2012-12-17 17:15:12 -08:00
binfmt_aout.c get rid of pt_regs argument of ->load_binary() 2012-11-28 21:53:38 -05:00
binfmt_elf_fdpic.c cputime: Use accessors to read task cputime stats 2013-01-27 19:23:31 +01:00
binfmt_elf.c cputime: Use accessors to read task cputime stats 2013-01-27 19:23:31 +01:00
binfmt_em86.c exec: use -ELOOP for max recursion depth 2012-12-17 17:15:23 -08:00
binfmt_flat.c get rid of pt_regs argument of ->load_binary() 2012-11-28 21:53:38 -05:00
binfmt_misc.c exec: do not leave bprm->interp on stack 2012-12-20 17:40:19 -08:00
binfmt_script.c exec: do not leave bprm->interp on stack 2012-12-20 17:40:19 -08:00
binfmt_som.c get rid of pt_regs argument of ->load_binary() 2012-11-28 21:53:38 -05:00
bio-integrity.c block: Ues bi_pool for bio_integrity_alloc() 2012-09-09 10:35:38 +02:00
bio.c vfs: fix: don't increase bio_slab_max if krealloc() fails 2012-10-22 22:00:26 +02:00
block_dev.c fs/block_dev.c: page cache wrongly left invalidated after revalidate_disk() 2013-02-21 17:22:16 -08:00
buffer.c mm: only enforce stable page writes if the backing device requires it 2013-02-21 17:22:19 -08:00
char_dev.c char_dev: pin parent kobject 2012-10-22 08:50:37 +03:00
compat_binfmt_elf.c coredump: extend core dump note section to contain file names of mapped files 2012-10-06 03:05:17 +09:00
compat_ioctl.c Merge 3.7-rc3 into tty-next 2012-10-29 09:00:57 -07:00
compat.c vfs: define struct filename and have getname() return it 2012-10-12 20:14:55 -04:00
coredump.c do_coredump(): get rid of pt_regs argument 2012-11-29 00:01:25 -05:00
coredump.h coredump: update coredump-related headers 2012-10-06 03:05:15 +09:00
dcache.c vfs: d_obtain_alias() needs to use "/" as default name. 2012-12-20 18:49:10 -05:00
dcookies.c
direct-io.c direct-io: don't read inode->i_blkbits multiple times 2012-11-29 12:38:44 -08:00
drop_caches.c
eventfd.c fs, eventfd: add procfs fdinfo helper 2012-12-17 17:15:27 -08:00
eventpoll.c epoll: prevent missed events on EPOLL_CTL_MOD 2013-01-02 09:16:43 -08:00
exec.c fs/exec.c: work around icc miscompilation 2013-01-11 14:54:55 -08:00
fcntl.c Fix F_DUPFD_CLOEXEC breakage 2012-10-09 15:52:31 +09:00
fhandle.c Merge branch 'for-3.8' of git://linux-nfs.org/~bfields/linux 2012-12-20 14:04:11 -08:00
fifo.c
file_table.c fs: Fix imbalance in freeze protection in mark_files_ro() 2012-12-20 13:57:36 -05:00
file.c misc: remove __dev* attributes. 2013-01-03 15:57:16 -08:00
filesystems.c vfs: define struct filename and have getname() return it 2012-10-12 20:14:55 -04:00
fs_struct.c kill daemonize() 2012-11-28 21:49:02 -05:00
fs-writeback.c writeback: fix a typo in comment 2012-12-12 17:38:34 -08:00
generic_acl.c userns: Pass a userns parameter into posix_acl_to_xattr and posix_acl_from_xattr 2012-09-18 01:01:35 -07:00
inode.c mm: redefine address_space.assoc_mapping 2012-12-11 17:22:26 -08:00
internal.h writeback: put unused inodes to LRU after writeback completion 2012-11-26 17:41:24 -08:00
ioctl.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
ioprio.c
Kconfig fuse: Move CUSE Kconfig entry from fs/Kconfig into fs/fuse/Kconfig 2013-01-17 13:08:45 +01:00
Kconfig.binfmt coredump: make core dump functionality optional 2012-10-06 03:05:15 +09:00
libfs.c vfs: drop vmtruncate 2012-12-20 18:46:29 -05:00
locks.c UAPI Disintegration 2012-10-09 2012-10-09 18:35:22 -04:00
Makefile f2fs: update Kconfig and Makefile 2012-12-11 13:43:42 +09:00
mbcache.c
mount.h proc: Usable inode numbers for the namespace file descriptors. 2012-11-20 04:19:49 -08:00
mpage.c
namei.c vfs: fix renameat to retry on ESTALE errors 2012-12-20 18:50:05 -05:00
namespace.c vfs, freeze: use ACCESS_ONCE() to guard access to ->mnt_flags 2012-12-20 13:36:18 -05:00
no-block.c
open.c vfs: make fchownat retry once on ESTALE errors 2012-12-20 18:50:07 -05:00
pipe.c pipe(2) - race-free error recovery 2012-09-26 21:08:52 -04:00
pnode.c
pnode.h vfs: Only support slave subtrees across different user namespaces 2012-11-19 05:59:20 -08:00
posix_acl.c userns: Convert vfs posix_acl support to use kuids and kgids 2012-09-18 01:01:35 -07:00
proc_namespace.c
read_write.c sendfile: allows bypassing of notifier events 2012-12-20 17:40:21 -08:00
read_write.h compat: fs: Generic compat_sys_sendfile implementation 2012-10-02 21:35:55 -04:00
readdir.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
select.c sched/rt: Move rt specific bits into new header file 2013-02-07 20:51:08 +01:00
seq_file.c seq_file: fix new kernel-doc warnings 2013-01-10 14:35:24 -08:00
signalfd.c fs, epoll: add procfs fdinfo helper 2012-12-17 17:15:27 -08:00
splice.c tcp: fix MSG_SENDPAGE_NOTLAST logic 2013-01-06 20:58:13 -08:00
stack.c
stat.c vfs: fix readlinkat to retry on ESTALE 2012-12-20 18:50:01 -05:00
statfs.c vfs: fix user_statfs to retry once on ESTALE errors 2012-12-20 18:50:07 -05:00
super.c vfs: drop lock/unlock super 2012-10-09 23:33:39 -04:00
sync.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
timerfd.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
utimes.c vfs: allow utimensat() calls to retry once on an ESTALE error 2012-12-20 18:50:08 -05:00
xattr_acl.c userns: Fix posix_acl_file_xattr_userns gid conversion 2012-10-12 13:16:48 -07:00
xattr.c vfs: make lremovexattr retry once on ESTALE error 2012-12-20 18:50:11 -05:00