Re: Performance regressions in 2.6.30-rc7?
From: Jan Kara
Date: Tue Jun 09 2009 - 06:39:58 EST
On Thu 04-06-09 21:13:15, Mike Galbraith wrote:
> On Thu, 2009-06-04 at 13:21 +0200, Jan Kara wrote:
>
> > > Sequential Writes
> > > 2.6.30-smp-ordered 6000 65536 32 50.16 508.9% 31.996 45595.78 0.64965 0.02402 10
> > > 2.6.29.4-smp-ordered 6000 65536 32 52.70 543.2% 33.658 23794.92 0.71754 0.00836 10
> > >
> > > 2.6.30-smp-writeback 6000 65536 32 47.82 525.4% 35.003 32588.84 0.56192 0.02298 9
> > > 2.6.29.4-smp-writeback 6000 65536 32 52.52 467.6% 32.397 12972.78 0.53580 0.00522 11
> > >
> > > 2.6.30-smp-ordered 6000 65536 16 56.08 254.9% 15.463 33000.68 0.39687 0.00521 22
> > > 2.6.29.4-smp-ordered 6000 65536 16 62.40 308.4% 14.701 13455.02 0.13125 0.00208 20
> > >
> > > 2.6.30-smp-writeback 6000 65536 16 51.90 281.4% 17.098 12869.85 0.36771 0.00104 18
> > > 2.6.29.4-smp-writeback 6000 65536 16 60.53 272.6% 14.977 8637.08 0.21146 0.00000 22
> > >
> > > 2.6.30-smp-ordered 6000 65536 8 51.09 113.4% 8.700 14856.55 0.06771 0.00417 45
> > > 2.6.29.4-smp-ordered 6000 65536 8 56.13 130.6% 8.098 8400.45 0.03958 0.00000 43
> > >
> > > 2.6.30-smp-writeback 6000 65536 8 50.19 131.7% 8.680 16821.04 0.11979 0.00208 38
> > > 2.6.29.4-smp-writeback 6000 65536 8 54.90 130.7% 8.244 4925.48 0.10000 0.00000 42
> > It really seems write has some problems... There's consistently lower
> > throughput and it also seems some writes take really long. I'll try to
> > reproduce it here.
>
> Looked "pretty solid" to me. I haven't observed enough to ~trust.
OK, I did a few runs of tiobench here and I can confirm that I see about
6% performance regression in Sequential Write throughput between 2.6.29
and 2.6.30-rc8. I'll try to find what's causing it.
Honza
--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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