| Date | Thu, 5 Mar 2009 09:09:20 +0800 | From | Wu Fengguang <> | Subject | Re: [Bug #12809] iozone regression with 2.6.29-rc6 |
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On Tue, Mar 03, 2009 at 09:25:59PM +0200, Rafael J. Wysocki wrote: > This message has been generated automatically as a part of a report > of recent regressions. > > The following bug entry is on the current list of known regressions > from 2.6.28. Please verify if it still should be listed and let me know > (either way). > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=12809 > Subject : iozone regression with 2.6.29-rc6 > Submitter : Lin Ming <ming.m.lin@intel.com> > Date : 2009-02-27 9:13 (5 days old) > First-Bad-Commit: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=1cf6e7d83bf334cc5916137862c920a97aabc018 > References : http://marc.info/?l=linux-kernel&m=123572630504360&w=4 > Handled-By : Wu Fengguang <fengguang.wu@intel.com>
Following Peter's idea of relaxing writeback throttling, Lin Ming and I tried the idea of totally disabling writeback throttling by doing benchmarks with the following parameters:
echo 60 > /proc/sys/vm/dirty_ratio echo 50 > /proc/sys/vm/dirty_background_ratio
The result is encouraging: the iozone performance is restored to the level of 2.6.29-rc5!
We'll continue to evaluate the dirty/throttling numbers with Nick's patch.
Thanks, Fengguang
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