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  1. 22 8月, 2014 4 次提交
  3. 20 8月, 2014 4 次提交
  5. 02 8月, 2014 1 次提交
  7. 31 7月, 2014 5 次提交
  9. 29 7月, 2014 4 次提交
  11. 12 7月, 2014 1 次提交
  13. 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
  15. 09 7月, 2014 2 次提交
  17. 08 6月, 2014 1 次提交
  19. 04 6月, 2014 2 次提交
  21. 07 5月, 2014 10 次提交
  23. 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
  25. 01 4月, 2014 1 次提交