Messages in this thread | | | Date | Tue, 23 Mar 2010 20:51:46 +0100 | From | Jesper Krogh <> | Subject | Re: Poor interactive performance with I/O loads with fsync()ing |
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Ben Gamari wrote: > Hey all, > > Recently I started using the Xapian-based notmuch mail client for everyday > use. One of the things I was quite surprised by after the switch was the > incredible hit in interactive performance that is observed during database > updates. Things are particularly bad during runs of 'notmuch new,' which scans > the file system looking for new messages and adds them to the database. > Specifically, the worst of the performance hit appears to occur when the > database is being updated.
I would suggest that you include a 2.6.31 kernel in your testing. I have seen something that seems like "huge" stalls in 2.6.32 but I havent been able to "dig into it" to find more.
In 2.6.32 I have seen IO-wait numbers around 80% on a 16 core machine with 128GB of memory and load-numbers over 120 under workloads that didn't make 2.6.31 sweat at all.
Filesystems are a mixture of ext3 and ext4 (so it could be the barriers)?
-- Jesper
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