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| author |   Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2014-04-02 15:34:36 +0900 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2014-04-07 09:50:58 +0900 |
| commit | 6b4afdd794783fe515b50838aa36591e3feea990 (patch) | |
| tree | 5f35f32e27db8deaf248cf1e7a4930aab0822a73 /Documentation/filesystems | |
| parent | f2fs: fix to cover io->bio with io_rwsem (diff) | |
| download | linux-dev-6b4afdd794783fe515b50838aa36591e3feea990.tar.xz linux-dev-6b4afdd794783fe515b50838aa36591e3feea990.zip | |
f2fs: introduce f2fs_issue_flush to avoid redundant flush issue
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: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/f2fs.txt | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt index 2f6d0218dd22..25311e113e75 100644 --- a/Documentation/filesystems/f2fs.txt +++ b/Documentation/filesystems/f2fs.txt @@ -122,6 +122,10 @@ disable_ext_identify Disable the extension list configured by mkfs, so f2fs inline_xattr Enable the inline xattrs feature. inline_data Enable the inline data feature: New created small(<~3.4k) files can be written into inode block. +flush_merge Merge concurrent cache_flush commands as much as possible + to eliminate redundant command issues. If the underlying + device handles the cache_flush command relatively slowly, + recommend to enable this option. ================================================================================ DEBUGFS ENTRIES |