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| author | Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp> | 2009-06-10 11:13:17 -0400 |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2009-06-10 11:29:53 -0400 |
| commit | 524724ed1f224875a117be593540591ed050c73d (patch) | |
| tree | 80f02291dc9f991dfd788d9ec6f4c8ee155997c7 | |
| parent | 163e783e6a8b1e8bcb4c9084d438091386b589df (diff) | |
Btrfs: fdatasync should skip metadata writeout
In btrfs, fdatasync and fsync are identical, but
fdatasync should skip committing transaction when
inode->i_state is set just I_DIRTY_SYNC and this indicates
only atime or/and mtime updates.
Following patch improves fdatasync throughput.
--file-block-size=4K --file-total-size=16G --file-test-mode=rndwr
--file-fsync-mode=fdatasync run
Results:
-2.6.30-rc8
Test execution summary:
total time: 1980.6540s
total number of events: 10001
total time taken by event execution: 1192.9804
per-request statistics:
min: 0.0000s
avg: 0.1193s
max: 15.3720s
approx. 95 percentile: 0.7257s
Threads fairness:
events (avg/stddev): 625.0625/151.32
execution time (avg/stddev): 74.5613/9.46
-2.6.30-rc8-patched
Test execution summary:
total time: 1695.9118s
total number of events: 10000
total time taken by event execution: 871.3214
per-request statistics:
min: 0.0000s
avg: 0.0871s
max: 10.4644s
approx. 95 percentile: 0.4787s
Threads fairness:
events (avg/stddev): 625.0000/131.86
execution time (avg/stddev): 54.4576/8.98
Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
| -rw-r--r-- | fs/btrfs/file.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 0726a734ee38..126477eaecf5 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1157,6 +1157,8 @@ int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync) btrfs_wait_ordered_range(inode, 0, (u64)-1); root->log_batch++; + if (datasync && !(inode->i_state & I_DIRTY_PAGES)) + goto out; /* * ok we haven't committed the transaction yet, lets do a commit */ |