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authorHisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>2009-06-10 17:13:17 +0200
committerChris Mason <chris.mason@oracle.com>2009-06-10 17:29:53 +0200
commit524724ed1f224875a117be593540591ed050c73d (patch)
tree80f02291dc9f991dfd788d9ec6f4c8ee155997c7 /fs
parentBtrfs: remove crc32c.h and use libcrc32c directly. (diff)
downloadlinux-524724ed1f224875a117be593540591ed050c73d.tar.xz
linux-524724ed1f224875a117be593540591ed050c73d.zip
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>
Diffstat (limited to 'fs')
-rw-r--r--fs/btrfs/file.c2
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
*/