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  1. 20 8月, 2014 4 次提交
  3. 02 8月, 2014 1 次提交
  5. 31 7月, 2014 5 次提交
  7. 29 7月, 2014 4 次提交
  9. 12 7月, 2014 1 次提交
  11. 10 7月, 2014 4 次提交
    • G
      f2fs: arguments cleanup of finding file flow functions · eee6160f
      由 Gu Zheng 提交于 
      Signed-off-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>
      eee6160f
    • C
      f2fs: refactor flush_nat_entries codes for reducing NAT writes · aec71382
      由 Chao Yu 提交于 
      Although building NAT journal in cursum reduce the read/write work for NAT
block, but previous design leave us lower performance when write checkpoint
frequently for these cases:
1. if journal in cursum has already full, it's a bit of waste that we flush all
   nat entries to page for persistence, but not to cache any entries.
2. if journal in cursum is not full, we fill nat entries to journal util
   journal is full, then flush the left dirty entries to disk without merge
   journaled entries, so these journaled entries may be flushed to disk at next
   checkpoint but lost chance to flushed last time.

In this patch we merge dirty entries located in same NAT block to nat entry set,
and linked all set to list, sorted ascending order by entries' count of set.
Later we flush entries in sparse set into journal as many as we can, and then
flush merged entries to disk. In this way we can not only gain in performance,
but also save lifetime of flash device.

In my testing environment, it shows this patch can help to reduce NAT block
writes obviously. In hard disk test case: cost time of fsstress is stablely
reduced by about 5%.

1. virtual machine + hard disk:
fsstress -p 20 -n 200 -l 5
		node num	cp count	nodes/cp
based		4599.6		1803.0		2.551
patched		2714.6		1829.6		1.483

2. virtual machine + 32g micro SD card:
fsstress -p 20 -n 200 -l 1 -w -f chown=0 -f creat=4 -f dwrite=0
-f fdatasync=4 -f fsync=4 -f link=0 -f mkdir=4 -f mknod=4 -f rename=5
-f rmdir=5 -f symlink=0 -f truncate=4 -f unlink=5 -f write=0 -S

		node num	cp count	nodes/cp
based		84.5		43.7		1.933
patched		49.2		40.0		1.23

Our latency of merging op shows not bad when handling extreme case like:
merging a great number of dirty nats:
latency(ns)	dirty nat count
3089219		24922
5129423		27422
4000250		24523

change log from v1:
 o fix wrong logic in add_nat_entry when grab a new nat entry set.
 o swith to create slab cache in create_node_manager_caches.
 o use GFP_ATOMIC instead of GFP_NOFS to avoid potential long latency.

change log from v2:
 o make comment position more appropriate suggested by Jaegeuk Kim.
Signed-off-by: NChao Yu <chao2.yu@samsung.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>
      aec71382
    • J
      f2fs: clean up an unused parameter and assignment · a014e037
      由 Jaegeuk Kim 提交于 
      This patch cleans up simple unnecessary codes.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>
      a014e037
    • J
      f2fs: introduce f2fs_do_tmpfile for code consistency · b97a9b5d
      由 Jaegeuk Kim 提交于 
      This patch adds f2fs_do_tmpfile to eliminate the redundant init_inode_metadata
flow.
Throught this, we can provide the consistent lock usage, e.g., fi->i_sem,  and
this will enable better debugging stuffs.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>
      b97a9b5d
  13. 09 7月, 2014 2 次提交
  15. 08 6月, 2014 1 次提交
  17. 04 6月, 2014 2 次提交
  19. 07 5月, 2014 10 次提交
  21. 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
  23. 01 4月, 2014 1 次提交
  25. 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
  27. 18 3月, 2014 1 次提交