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List:       openjdk-2d-dev
Subject:    [OpenJDK 2D-Dev] Integrated: 8263482: Make access to the ICC color profiles data multithread-friendl
From:       Sergey Bylokhov <serb () openjdk ! java ! net>
Date:       2021-03-19 2:51:38
Message-ID: 3NHsCVboGu1I1PCtY4_FIX5mV-UFs5gDS7XpkqHVb3c=.ce65ca97-7c6b-4918-91e5-6b6be3dfdfda () github ! com
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On Fri, 12 Mar 2021 05:10:25 GMT, Sergey Bylokhov <serb@openjdk.org> wrote:

> FYI: probably is better/simpler to review it via webrev.
> 
> After migration to the lcms from the kcms the performance of some operations was \
> regressed. One possible workaround was to split the operation into multiple \
> threads. But unfortunately, we have too many bottlenecks which prevent using \
> multithreading. This is the request to remove/minimize such bottlenecks(at least \
> some of them), but it does not affect the single-threaded performance it should be \
> handled separately. 
> The main code pattern optimized here is this:
> activate();
> byte[] theHeader = getData(cmmProfile, icSigHead);
> ---->  CMSManager.getModule().getTagData(p, tagSignature);
> Notes about the code above:
> 
> 1. Before the change "activate()" method checked that the "cmmProfile" field was \
> not null. After that we usually used the "cmmProfile" as the parameter to some \
> other method. This included two volatile reads, and also required to check when we \
>                 need to call the "activate()" method before usage of the \
>                 "cmmProfile" field.
> Solution: "activate()" renamed to the "cmmProfile()" which became an accessor for \
> the field, so we will get one volatile read and can easily monitor the usage of the \
> field itself(it is used directly only in this method). 
> 2. The synchronized static method "CMSManager.getModule()" reimplemented to have \
> only one volatile read. 
> 3. The usage of locking in the "getTagData()" is changed. Instead of the \
> synchronized instance methods, we now use the mix of "ConcurrentHashMap" and \
> StampedLock. 
> See some comments inline.
> 
> Some numbers(small numbers are better):
> 
> 1. Performance of ((ICC_ProfileRGB) \
> ICC_Profile.getInstance(ColorSpace.CS_sRGB)).getMatrix(); 
> jdk 15.0.2
> Benchmark                              Mode  Cnt    Score      Error  Units
> CMMPerf.ThreadsMAX.testGetMatrix       avgt    5   19,624  ±    0,059  us/op
> CMMPerf.testGetMatrix                  avgt    5    0,154  ±    0,001  us/op
> 
> jdk - before the fix
> Benchmark                              Mode  Cnt    Score      Error  Units
> CMMPerf.ThreadsMAX.testGetMatrix       avgt    5   12,935  ±    0,042  us/op
> CMMPerf.testGetMatrix                  avgt    5    0,127  ±    0,007  us/op
> 
> jdk - after the fix
> Benchmark                              Mode  Cnt    Score      Error  Units
> CMMPerf.ThreadsMAX.testGetMatrix       avgt    5    0,561  ±    0,005  us/op
> CMMPerf.testGetMatrix                  avgt    5    0,092  ±    0,001  us/op
> 
> 2. Part of performance gain in jdk17 is from some other fixes, for example
> Performance of ICC_Profile.getInstance(ColorSpace.CS_sRGB); and \
> ColorSpace.getInstance(ColorSpace.CS_sRGB); 
> jdk 15.0.2
> Benchmark                              Mode  Cnt    Score      Error  Units
> CMMPerf.ThreadsMAX.testGetSRGBProfile  avgt    5    2,299  ±    0,032  us/op
> CMMPerf.ThreadsMAX.testGetSRGBSpace    avgt    5    2,210  ±    0,051  us/op
> CMMPerf.testGetSRGBProfile             avgt    5    0,019  ±    0,001  us/op
> CMMPerf.testGetSRGBSpace               avgt    5    0,018  ±    0,001  us/op
> 
> jdk - same before/ after the fix
> Benchmark                              Mode  Cnt    Score      Error  Units
> CMMPerf.ThreadsMAX.testGetSRGBProfile  avgt    5    0,005  ±    0,001  us/op
> CMMPerf.ThreadsMAX.testGetSRGBSpace    avgt    5    0,005  ±    0,001  us/op
> CMMPerf.testGetSRGBProfile             avgt    5    0,005  ±    0,001  us/op
> CMMPerf.testGetSRGBSpace               avgt    5    0,005  ±    0,001  us/op
> 
> note "ThreadsMAX" is 32 threads.

This pull request has now been integrated.

Changeset: 1a21f779
Author:    Sergey Bylokhov <serb@openjdk.org>
URL:       https://git.openjdk.java.net/jdk/commit/1a21f779
Stats:     212 lines in 5 files changed: 52 ins; 83 del; 77 mod

8263482: Make access to the ICC color profiles data multithread-friendly

Reviewed-by: azvegint

-------------

PR: https://git.openjdk.java.net/jdk/pull/2957


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