Integrated: 8041125: ColorConvertOp filter much slower in JDK 8 compared to JDK7

[Sergey Bylokhov]

On Wed, 6 Oct 2021 08:41:38 GMT, Sergey Bylokhov <serb at openjdk.org> wrote:

> We have improved the cmm code over a few releases and mostly resolve the JDK-8041125. But I have executed an attached test case under a profiler and found that:
> 
> * less than 10% is an actual pixel transformation inside littlecms
> * 30% is a native up-calls like getXXField
> * 30% is incoming arrays coping
> * 30% results array saving
> * others
> 
> This change removes the native up-calls and passes all data from the java side.
> 
> Notes:
> 
> * The above numbers are true for the "pure Java" implementation in the test case, where we transform the image pixel by pixel, if the image is big and we transform it at once via filter then we spend most of the time in the littlecms code
> * JDK7 uses 4 threads in the filter implementation, but single-threaded jdk17 is faster because of some code improvement in cmm profiles initialization during the "cold start". And probably because the image is not so big(625x843).
> * If the size of the image will be increased and the warmup is done the jdk7 will be 4x time faster, this is another opportunity that I'll try to resolve later.
> 
> 
> Tested on macOS (fastest result after a few runs):
> ||JDK 7 | JDK 8 | JDK 17 | FIX |
> |----|----|----|----|----|
> |With filter |  307 ms  |  456 ms  |  242 ms  |   236 ms |
> |In pure Java|  1672 ms  |  389 ms  |  300 ms  |  259 ms  |
> 
> 
> JMH before/after the fix
> `ColorSpace.toRGB/fromRGB/toCIEXYZ/fromCIEXYZ(new float[]{1,1,1})`
> single threaded and multi-threaded(MAX = 30):
> ![image](https://user-images.githubusercontent.com/14138494/136283699-05e47dca-e7f8-43a1-97d3-53072d3589f6.png)
> 
> https://jmh.morethan.io/?gists=b1edd5e5ebeb1b76867b2112be30145d,fc86ce4a6f8f2f49e9ab512ef641c11b

This pull request has now been integrated.

Changeset: c355704a
Author:    Sergey Bylokhov <serb at openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/c355704a4b3d376b5429daba1576442b575f41ea
Stats:     137 lines in 4 files changed: 9 ins; 101 del; 27 mod

8041125: ColorConvertOp filter much slower in JDK 8 compared to JDK7

Reviewed-by: prr

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PR: https://git.openjdk.java.net/jdk/pull/5835