Messages in this thread | | | Date | Sun, 11 Apr 2010 19:20:07 +0200 | From | Andi Kleen <> | Subject | Re: Poor interactive performance with I/O loads with fsync()ing |
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> Has the reason for this been identified? Judging from the nature of metadata > loads, it would seem that it should be substantially easier to implement > fsync() efficiently.
By design a copy on write tree fs would need to flush a whole tree hierarchy on a sync. btrfs avoids this by using a special log for fsync, but that causes more overhead if you have that log on the same disk. So IO subsystem will do more work.
It's a bit like JBD data journaling.
However it should not have the stalls inherent in ext3's journaling.
-Andi -- ak@linux.intel.com -- Speaking for myself only.
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