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  1. 07 5月, 2014 6 次提交
  3. 07 4月, 2014 1 次提交
    • J
      f2fs: introduce f2fs_issue_flush to avoid redundant flush issue · 6b4afdd7
      由 Jaegeuk Kim 提交于 
      Some storage devices show relatively high latencies to complete cache_flush
commands, even though their normal IO speed is prettry much high. In such
the case, it needs to merge cache_flush commands as much as possible to avoid
issuing them redundantly.
So, this patch introduces a mount option, "-o flush_merge", to mitigate such
the overhead.

If this option is enabled by user, F2FS merges the cache_flush commands and then
issues just one cache_flush on behalf of them. Once the single command is
finished, F2FS sends a completion signal to all the pending threads.

Note that, this option can be used under a workload consisting of very intensive
concurrent fsync calls, while the storage handles cache_flush commands slowly.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
      6b4afdd7
  5. 01 4月, 2014 1 次提交
  7. 20 3月, 2014 3 次提交
    • J
      f2fs: skip unnecessary node writes during fsync · 479f40c4
      由 Jaegeuk Kim 提交于 
      If multiple redundant fsync calls are triggered, we don't need to write its
node pages with fsync mark continuously.

So, this patch adds FI_NEED_FSYNC to track whether the latest node block is
written with the fsync mark or not.
If the mark was set, a new fsync doesn't need to write a node block.
Otherwise, we should do a new node block with the mark for roll-forward
recovery.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
      479f40c4
    • J
      f2fs: introduce fi->i_sem to protect fi's info · d928bfbf
      由 Jaegeuk Kim 提交于 
      This patch introduces fi->i_sem to protect fi's info that includes xattr_ver,
pino, i_nlink.
This enables to remove i_mutex during f2fs_sync_file, resulting in performance
improvement when a number of fsync calls are triggered from many concurrent
threads.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
      d928bfbf
    • J
      f2fs: throttle the memory footprint with a sysfs entry · cdfc41c1
      由 Jaegeuk Kim 提交于 
      This patch introduces ram_thresh, a sysfs entry, which controls the memory
footprint used by the free nid list and the nat cache.

Previously, the free nid list was controlled by MAX_FREE_NIDS, while the nat
cache was managed by NM_WOUT_THRESHOLD.
However, this approach cannot be applied dynamically according to the system.

So, this patch adds ram_thresh that users can specify the threshold, which is
in order of 1 / 1024.
For example, if the total ram size is 4GB and the value is set to 10 by default,
f2fs tries to control the number of free nids and nat caches not to consume over
10 * (4GB / 1024) = 10MB.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
      cdfc41c1
  9. 18 3月, 2014 2 次提交
  11. 12 3月, 2014 1 次提交
  13. 10 3月, 2014 1 次提交
  15. 27 2月, 2014 4 次提交
    • C
      f2fs: use existing macro to clean up some codes · 695fd1ed
      由 Chao Yu 提交于 
      This patch use existing macro F2FS_INODE/NEXT_FREE_BLKADDR to clean up some
codes.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
      695fd1ed
    • C
      f2fs: readahead contiguous SSA blocks for f2fs_gc · 81c1a0f1
      由 Chao Yu 提交于 
      If there are multi segments in one section, we will read those SSA blocks which
have contiguous address one by one in f2fs_gc. It may lost performance, let's
read ahead SSA blocks by merge multi read request.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
      81c1a0f1
    • J
      f2fs: add an sysfs entry to control the directory level · ab9fa662
      由 Jaegeuk Kim 提交于 
      This patch adds an sysfs entry to control dir_level used by the large directory.

The description of this entry is:

 dir_level                    This parameter controls the directory level to
			      support large directory. If a directory has a
			      number of files, it can reduce the file lookup
			      latency by increasing this dir_level value.
			      Otherwise, it needs to decrease this value to
			      reduce the space overhead. The default value is 0.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
      ab9fa662
    • J
      f2fs: introduce large directory support · 38431545
      由 Jaegeuk Kim 提交于 
      This patch introduces an i_dir_level field to support large directory.

Previously, f2fs maintains multi-level hash tables to find a dentry quickly
from a bunch of chiild dentries in a directory, and the hash tables consist of
the following tree structure as below.

In Documentation/filesystems/f2fs.txt,

----------------------
A : bucket
B : block
N : MAX_DIR_HASH_DEPTH
----------------------

level #0   | A(2B)
           |
level #1   | A(2B) - A(2B)
           |
level #2   | A(2B) - A(2B) - A(2B) - A(2B)
     .     |   .       .       .       .
level #N/2 | A(2B) - A(2B) - A(2B) - A(2B) - A(2B) - ... - A(2B)
     .     |   .       .       .       .
level #N   | A(4B) - A(4B) - A(4B) - A(4B) - A(4B) - ... - A(4B)

But, if we can guess that a directory will handle a number of child files,
we don't need to traverse the tree from level #0 to #N all the time.
Since the lower level tables contain relatively small number of dentries,
the miss ratio of the target dentry is likely to be high.

In order to avoid that, we can configure the hash tables sparsely from level #0
like this.

level #0   | A(2B) - A(2B) - A(2B) - A(2B)

level #1   | A(2B) - A(2B) - A(2B) - A(2B) - A(2B) - ... - A(2B)
     .     |   .       .       .       .
level #N/2 | A(2B) - A(2B) - A(2B) - A(2B) - A(2B) - ... - A(2B)
     .     |   .       .       .       .
level #N   | A(4B) - A(4B) - A(4B) - A(4B) - A(4B) - ... - A(4B)

With this structure, we can skip the ineffective tree searches in lower level
hash tables.

This patch adds just a facility for this by introducing i_dir_level in
f2fs_inode.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
      38431545
  17. 24 2月, 2014 3 次提交
  19. 17 2月, 2014 7 次提交
  21. 26 1月, 2014 1 次提交
  23. 22 1月, 2014 2 次提交
  25. 20 1月, 2014 1 次提交
  27. 14 1月, 2014 2 次提交
  29. 08 1月, 2014 2 次提交
    • J
      f2fs: add a sysfs entry to control max_victim_search · b1c57c1c
      由 Jaegeuk Kim 提交于 
      Previously during SSR and GC, the maximum number of retrials to find a victim
segment was hard-coded by MAX_VICTIM_SEARCH, 4096 by default.

This number makes an effect on IO locality, when SSR mode is activated, which
results in performance fluctuation on some low-end devices.

If max_victim_search = 4, the victim will be searched like below.
("D" represents a dirty segment, and "*" indicates a selected victim segment.)

 D1 D2 D3 D4 D5 D6 D7 D8 D9
[   *       ]
      [   *    ]
            [         * ]
	                [ ....]

This patch adds a sysfs entry to control the number dynamically through:
  /sys/fs/f2fs/$dev/max_victim_search
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
      b1c57c1c
    • J
      f2fs: improve write performance under frequent fsync calls · fb5566da
      由 Jaegeuk Kim 提交于 
      When considering a bunch of data writes with very frequent fsync calls, we
are able to think the following performance regression.

N: Node IO, D: Data IO, IO scheduler: cfq

Issue    pending IOs
	 D1 D2 D3 D4
 D1         D2 D3 D4 N1
 D2            D3 D4 N1 N2
 N1            D3 D4 N2 D1
 --> N1 can be selected by cfq becase of the same priority of N and D.
     Then D3 and D4 would be delayed, resuling in performance degradation.

So, when processing the fsync call, it'd better give higher priority to data IOs
than node IOs by assigning WRITE and WRITE_SYNC respectively.
This patch improves the random wirte performance with frequent fsync calls by up
to 10%.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
      fb5566da
  31. 06 1月, 2014 3 次提交
    • J
      f2fs: add inline_data recovery routine · 1e1bb4ba
      由 Jaegeuk Kim 提交于 
      This patch adds a inline_data recovery routine with the following policy.

[prev.] [next] of inline_data flag
   o       o  -> recover inline_data
   o       x  -> remove inline_data, and then recover data blocks
   x       o  -> remove inline_data, and then recover inline_data
   x       x  -> recover data blocks
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
      1e1bb4ba
    • J
      f2fs: add the number of inline_data files to status info · 0dbdc2ae
      由 Jaegeuk Kim 提交于 
      This patch adds the number of inline_data files into the status information.
Note that the number is reset whenever the filesystem is newly mounted.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
      0dbdc2ae
    • J
      f2fs: refactor f2fs_convert_inline_data · 9e09fc85
      由 Jaegeuk Kim 提交于 
      Change log from v1:
 o handle NULL pointer of grab_cache_page_write_begin() pointed by Chao Yu.

This patch refactors f2fs_convert_inline_data to check a couple of conditions
internally for deciding whether it needs to convert inline_data or not.

So, the new f2fs_convert_inline_data initially checks:
1) f2fs_has_inline_data(), and
2) the data size to be changed.

If the inode has inline_data but the size to fill is less than MAX_INLINE_DATA,
then we don't need to convert the inline_data with data allocation.
Signed-off-by: NJaegeuk Kim <jaegeuk.kim@samsung.com>
      9e09fc85