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
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
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
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
pnode.c
pnode.h	vfs: Only support slave subtrees across different user namespaces	2012-11-19 05:59:20 -08:00
posix_acl.c
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