Re: [PATCH 0/3] Shrinkers and proportional reclaim

From: Yuanhan Liu
Date: Thu May 22 2014 - 12:13:00 EST


On Thu, May 22, 2014 at 10:09:36AM +0100, Mel Gorman wrote:
> This series is aimed at regressions noticed during reclaim activity. The
> first two patches are shrinker patches that were posted ages ago but never
> merged for reasons that are unclear to me. I'm posting them again to see if
> there was a reason they were dropped or if they just got lost. Dave? Time?
> The last patch adjusts proportional reclaim. Yuanhan Liu, can you retest
> the vm scalability test cases on a larger machine? Hugh, does this work
> for you on the memcg test cases?

Sure, and here is the result. I applied these 3 patches on v3.15-rc6,
and head commit is 60c10afd. e82e0561 is the old commit that introduced
the regression. The testserver has 512G memory and 120 CPU.

It's a simple result; if you need more data, I can gather them and send
it to you tomorrow:

e82e0561 v3.15-rc6 60c10afd
----------------------------------------
18560785 12232122 38868453
-34% +109

As you can see, the performance is back, and it is way much better ;)

--yliu
>
> Based on ext4, I get the following results but unfortunately my larger test
> machines are all unavailable so this is based on a relatively small machine.
>
> postmark
> 3.15.0-rc5 3.15.0-rc5
> vanilla proportion-v1r4
> Ops/sec Transactions 21.00 ( 0.00%) 25.00 ( 19.05%)
> Ops/sec FilesCreate 39.00 ( 0.00%) 45.00 ( 15.38%)
> Ops/sec CreateTransact 10.00 ( 0.00%) 12.00 ( 20.00%)
> Ops/sec FilesDeleted 6202.00 ( 0.00%) 6202.00 ( 0.00%)
> Ops/sec DeleteTransact 11.00 ( 0.00%) 12.00 ( 9.09%)
> Ops/sec DataRead/MB 25.97 ( 0.00%) 30.02 ( 15.59%)
> Ops/sec DataWrite/MB 49.99 ( 0.00%) 57.78 ( 15.58%)
>
> ffsb (mail server simulator)
> 3.15.0-rc5 3.15.0-rc5
> vanilla proportion-v1r4
> Ops/sec readall 9402.63 ( 0.00%) 9805.74 ( 4.29%)
> Ops/sec create 4695.45 ( 0.00%) 4781.39 ( 1.83%)
> Ops/sec delete 173.72 ( 0.00%) 177.23 ( 2.02%)
> Ops/sec Transactions 14271.80 ( 0.00%) 14764.37 ( 3.45%)
> Ops/sec Read 37.00 ( 0.00%) 38.50 ( 4.05%)
> Ops/sec Write 18.20 ( 0.00%) 18.50 ( 1.65%)
>
> dd of a large file
> 3.15.0-rc5 3.15.0-rc5
> vanilla proportion-v1r4
> WallTime DownloadTar 75.00 ( 0.00%) 61.00 ( 18.67%)
> WallTime DD 423.00 ( 0.00%) 401.00 ( 5.20%)
> WallTime Delete 2.00 ( 0.00%) 5.00 (-150.00%)
>
> stutter (times mmap latency during large amounts of IO)
>
> 3.15.0-rc5 3.15.0-rc5
> vanilla proportion-v1r4
> Unit >5ms Delays 80252.0000 ( 0.00%) 81523.0000 ( -1.58%)
> Unit Mmap min 8.2118 ( 0.00%) 8.3206 ( -1.33%)
> Unit Mmap mean 17.4614 ( 0.00%) 17.2868 ( 1.00%)
> Unit Mmap stddev 24.9059 ( 0.00%) 34.6771 (-39.23%)
> Unit Mmap max 2811.6433 ( 0.00%) 2645.1398 ( 5.92%)
> Unit Mmap 90% 20.5098 ( 0.00%) 18.3105 ( 10.72%)
> Unit Mmap 93% 22.9180 ( 0.00%) 20.1751 ( 11.97%)
> Unit Mmap 95% 25.2114 ( 0.00%) 22.4988 ( 10.76%)
> Unit Mmap 99% 46.1430 ( 0.00%) 43.5952 ( 5.52%)
> Unit Ideal Tput 85.2623 ( 0.00%) 78.8906 ( 7.47%)
> Unit Tput min 44.0666 ( 0.00%) 43.9609 ( 0.24%)
> Unit Tput mean 45.5646 ( 0.00%) 45.2009 ( 0.80%)
> Unit Tput stddev 0.9318 ( 0.00%) 1.1084 (-18.95%)
> Unit Tput max 46.7375 ( 0.00%) 46.7539 ( -0.04%)
>
> fs/super.c | 16 +++++++++-------
> mm/vmscan.c | 36 +++++++++++++++++++++++++-----------
> 2 files changed, 34 insertions(+), 18 deletions(-)
>
> --
> 1.8.4.5
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