Messages in this thread | | | From | Con Kolivas <> | Subject | Re: cfq misbehaving on 2.6.11-1.14_FC3 | Date | Fri, 24 Jun 2005 09:33:53 +1000 |
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On Fri, 24 Jun 2005 04:30, spaminos-ker@yahoo.com wrote: > --- Jens Axboe <axboe@suse.de> wrote: > > Journalled file systems will behave worse for this, because it has to > > tend to the journal as well. Can you try mounting that partition as ext2 > > and see what numbers that gives you? > > I did the tests again on a partition that I could mkfs/mount at will. > > On ext3, I get about 33 seconds average latency. > > And on ext2, as predicted, I have latencies in average of about 0.4 > seconds. > > I also tried reiserfs, and it gets about 22 seconds latency. > > As you pointed out, it seems that there is a flow in the way IO queues and > journals (that are in some ways queues as well), interact in the presence > of flushes.
I found the same, and the effect was blunted by noatime and journal_data_writeback (on ext3). Try them one at a time and see what you get.
Cheers, Con [unhandled content-type:application/pgp-signature] | |