Liu Bo 67c9684f48 Btrfs: improve multi-thread buffer read ... While testing with my buffer read fio jobs[1], I find that btrfs does not perform well enough. Here is a scenario in fio jobs: We have 4 threads, "t1 t2 t3 t4", starting to buffer read a same file, and all of them will race on add_to_page_cache_lru(), and if one thread successfully puts its page into the page cache, it takes the responsibility to read the page's data. And what's more, reading a page needs a period of time to finish, in which other threads can slide in and process rest pages: t1 t2 t3 t4 add Page1 read Page1 add Page2 | read Page2 add Page3 | | read Page3 add Page4 | | | read Page4 -----|------------|-----------|-----------|-------- v v v v bio bio bio bio Now we have four bios, each of which holds only one page since we need to maintain consecutive pages in bio. Thus, we can end up with far more bios than we need. Here we're going to a) delay the real read-page section and b) try to put more pages into page cache. With that said, we can make each bio hold more pages and reduce the number of bios we need. Here is some numbers taken from fio results: w/o patch w patch ------------- -------- --------------- READ: 745MB/s +25% 934MB/s [1]: [global] group_reporting thread numjobs=4 bs=32k rw=read ioengine=sync directory=/mnt/btrfs/ [READ] filename=foobar size=2000M invalidate=1 Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>		2012-07-23 16:28:10 -04:00
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acl.c	Btrfs: cache no acl on new inodes	2012-05-30 10:23:27 -04:00
async-thread.c	btrfs: return void in functions without error conditions	2012-03-22 01:45:34 +01:00
async-thread.h	btrfs: return void in functions without error conditions	2012-03-22 01:45:34 +01:00
backref.c	Btrfs: leave critical region in btrfs_find_all_roots as soon as possible	2012-06-27 16:34:39 +02:00
backref.h	Btrfs: use the tree modification log for backref resolving	2012-05-30 15:17:34 +02:00
btrfs_inode.h	Btrfs: kill free_space pointer from inode structure	2012-07-23 16:28:05 -04:00
check-integrity.c	Btrfs: use rcu to protect device->name	2012-06-14 21:29:16 -04:00
check-integrity.h	Btrfs: add optional integrity check code	2011-12-21 19:14:09 +01:00
compat.h	Btrfs: drop remaining LINUX_KERNEL_VERSION checks and compat code	2009-01-06 09:38:55 -05:00
compression.c	Merge branch 'for-linus-min' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs	2012-04-13 19:41:27 -07:00
compression.h	btrfs: return void in functions without error conditions	2012-03-22 01:45:34 +01:00
ctree.c	Btrfs: fix buffer leak in btrfs_next_old_leaf	2012-07-23 16:28:03 -04:00
ctree.h	Btrfs: rewrite BTRFS_SETGET_FUNCS	2012-07-23 16:28:06 -04:00
delayed-inode.c	Btrfs: zero unused bytes in inode item	2012-07-23 16:28:05 -04:00
delayed-inode.h	Btrfs: flush delayed inodes if we're short on space	2012-07-23 15:41:40 -04:00
delayed-ref.c	Btrfs: use delayed ref sequence numbers for all fs-tree updates	2012-05-30 18:18:21 +02:00
delayed-ref.h	Btrfs: use delayed ref sequence numbers for all fs-tree updates	2012-05-30 18:18:21 +02:00
dir-item.c	btrfs: replace many BUG_ONs with proper error handling	2012-03-22 11:52:54 +01:00
disk-io.c	Btrfs: avoid I/O repair BUG() from btree_read_extent_buffer_pages()	2012-07-23 16:27:59 -04:00
disk-io.h	btrfs: Drop unused function btrfs_abort_devices()	2012-05-30 10:23:39 -04:00
export.c	->encode_fh() API change	2012-05-29 23:28:33 -04:00
export.h	NFS support for btrfs - v3	2008-09-25 11:04:06 -04:00
extent_io.c	Btrfs: improve multi-thread buffer read	2012-07-23 16:28:10 -04:00
extent_io.h	Merge branch 'for-chris' of git://git.jan-o-sch.net/btrfs-unstable into for-linus	2012-05-31 16:49:53 -04:00
extent_map.c	Btrfs: clean up code for merging extent maps	2011-08-01 14:30:50 -04:00
extent_map.h	btrfs: fix structs where bitfields and spinlock/atomic share 8B word	2012-02-15 16:40:25 +01:00
extent-tree.c	Btrfs: make btrfs's allocation smoothly with preallocation	2012-07-23 16:28:10 -04:00
file-item.c	Btrfs: kill root from btrfs_is_free_space_inode	2012-07-23 16:28:00 -04:00
file.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs	2012-07-05 13:06:25 -07:00
free-space-cache.c	Btrfs: do not count in readonly bytes	2012-07-23 16:28:03 -04:00
free-space-cache.h	btrfs: remove all unused functions	2011-05-06 12:34:03 +02:00
hash.h	Btrfs: remove crc32c.h and use libcrc32c directly.	2009-06-10 11:29:53 -04:00
inode-item.c	Merge branch 'error-handling' into for-linus	2012-03-28 20:31:37 -04:00
inode-map.c	Btrfs: show useful info in space reservation tracepoint	2012-03-29 09:57:44 -04:00
inode-map.h	Btrfs: Support reading/writing on disk free ino cache	2011-04-25 16:46:11 +08:00
inode.c	Btrfs: zero unused bytes in inode item	2012-07-23 16:28:05 -04:00
ioctl.c	Btrfs: do not set subvolume flags in readonly mode	2012-07-23 16:27:58 -04:00
ioctl.h	Btrfs: add DEVICE_READY ioctl	2012-07-23 16:27:42 -04:00
Kconfig	Btrfs: add config option to enable btrfs integrity check	2011-12-21 19:14:16 +01:00
locking.c	Btrfs: reduce calls to wake_up on uncontended locks	2012-07-23 15:36:18 -04:00
locking.h	btrfs: return void in functions without error conditions	2012-03-22 01:45:34 +01:00
lzo.c	btrfs: remove the second argument of k[un]map_atomic()	2012-03-20 21:48:21 +08:00
Makefile	Merge branch 'integrity-check-patch-v2' of git://btrfs.giantdisaster.de/git/btrfs into integration	2012-01-16 15:27:58 -05:00
ordered-data.c	Btrfs: call filemap_fdatawrite twice for compression	2012-06-14 21:30:54 -04:00
ordered-data.h	Btrfs: finish ordered extents in their own thread	2012-05-30 10:23:33 -04:00
orphan.c	btrfs: replace many BUG_ONs with proper error handling	2012-03-22 11:52:54 +01:00
print-tree.c	Btrfs: read device stats on mount, write modified ones during commit	2012-05-30 10:23:41 -04:00
print-tree.h	Btrfs: Create extent_buffer interface for large blocksizes	2008-09-25 11:03:56 -04:00
rcu-string.h	Btrfs: use rcu to protect device->name	2012-06-14 21:29:16 -04:00
reada.c	Btrfs: set ioprio of scrub readahead to idle	2012-05-30 10:23:43 -04:00
relocation.c	Btrfs: fix error handling in __add_reloc_root()	2012-07-23 16:27:53 -04:00
root-tree.c	btrfs: replace many BUG_ONs with proper error handling	2012-03-22 11:52:54 +01:00
scrub.c	Btrfs: use rcu to protect device->name	2012-06-14 21:29:16 -04:00
struct-funcs.c	Btrfs: rewrite BTRFS_SETGET_FUNCS	2012-07-23 16:28:06 -04:00
super.c	Btrfs: add DEVICE_READY ioctl	2012-07-23 16:27:42 -04:00
sysfs.c	btrfs: Remove unused sysfs code	2011-06-17 14:54:18 -04:00
transaction.c	Btrfs: change how we indicate we're adding csums	2012-07-23 16:27:55 -04:00
transaction.h	Btrfs: change how we indicate we're adding csums	2012-07-23 16:27:55 -04:00
tree-defrag.c	btrfs: drop unused parameter from btrfs_release_path	2011-05-02 13:57:22 +02:00
tree-log.c	Btrfs: return error of btrfs_update_inode() to caller	2012-07-23 16:27:54 -04:00
tree-log.h	btrfs: return void in functions without error conditions	2012-03-22 01:45:34 +01:00
ulist.c	Merge branch 'for-chris' of git://git.jan-o-sch.net/btrfs-unstable into for-linus	2012-05-31 16:49:53 -04:00
ulist.h	Merge branch 'for-chris' of git://git.jan-o-sch.net/btrfs-unstable into for-linus	2012-05-31 16:49:53 -04:00
version.h	Update Btrfs files for in-kernel usage	2008-09-25 15:41:59 -04:00
volumes.c	Btrfs: suppress printk() if all device I/O stats are zero	2012-07-23 16:28:07 -04:00
volumes.h	Btrfs: add DEVICE_READY ioctl	2012-07-23 16:27:42 -04:00
xattr.c	Btrfs: use i_version instead of our own sequence	2012-05-30 10:23:27 -04:00
xattr.h	fs/vfs/security: pass last path component to LSM on inode creation	2011-02-01 11:12:29 -05:00
zlib.c	btrfs: remove the second argument of k[un]map_atomic()	2012-03-20 21:48:21 +08:00