On Thu, Apr 23, 2020 at 10:56 AM Laurent Bourgès <[email protected]> wrote: > > Hi Volker, > > Could you give some benchmark results in the jbs bug to have an idea of the > performance gain ?
The results of a benchmark run are at the end of the microbenchmark which is attached to https://bugs.openjdk.java.net/browse/JDK-8242848 I've attached them here for your convenience. The first run is before, the second run after applying this patch. E.g. for a user supplied buffer of size 16384, the time for inflation decreases from "2.603 ± 0.404 ms/op" to "2.187 ± 0.126 ms/op" which is an improvement of 16%. Obviously, increasing the default internal buffer size from 512 to 16384 (which I want to do in https://bugs.openjdk.java.net/browse/JDK-8242864) will get you even bigger speedups if you use the default buffer size :) /output/jdk-opt/images/jdk/bin/java ---------------------------------------------------------------------- Benchmark (scale) (size) Mode Cnt Score Error Units InflaterOutputStreamWrite.write 1 512 avgt 3 5.378 ± 0.301 ms/op InflaterOutputStreamWrite.write 1 1024 avgt 3 3.917 ± 0.165 ms/op InflaterOutputStreamWrite.write 1 2048 avgt 3 3.158 ± 0.097 ms/op InflaterOutputStreamWrite.write 1 4096 avgt 3 2.707 ± 0.138 ms/op InflaterOutputStreamWrite.write 1 8192 avgt 3 2.600 ± 0.399 ms/op InflaterOutputStreamWrite.write 1 16384 avgt 3 2.603 ± 0.404 ms/op InflaterOutputStreamWrite.write 1 32768 avgt 3 2.622 ± 0.211 ms/op InflaterOutputStreamWrite.write 1 65536 avgt 3 2.605 ± 0.170 ms/op InflaterOutputStreamWrite.write 2 512 avgt 3 4.015 ± 0.150 ms/op InflaterOutputStreamWrite.write 2 1024 avgt 3 3.225 ± 0.178 ms/op InflaterOutputStreamWrite.write 2 2048 avgt 3 2.745 ± 0.261 ms/op InflaterOutputStreamWrite.write 2 4096 avgt 3 2.614 ± 0.542 ms/op InflaterOutputStreamWrite.write 2 8192 avgt 3 2.593 ± 0.206 ms/op InflaterOutputStreamWrite.write 2 16384 avgt 3 2.606 ± 0.055 ms/op InflaterOutputStreamWrite.write 2 32768 avgt 3 2.611 ± 0.116 ms/op InflaterOutputStreamWrite.write 2 65536 avgt 3 2.617 ± 0.170 ms/op InflaterOutputStreamWrite.write 4 512 avgt 3 3.376 ± 0.599 ms/op InflaterOutputStreamWrite.write 4 1024 avgt 3 2.840 ± 0.155 ms/op InflaterOutputStreamWrite.write 4 2048 avgt 3 2.633 ± 0.550 ms/op InflaterOutputStreamWrite.write 4 4096 avgt 3 2.598 ± 0.166 ms/op InflaterOutputStreamWrite.write 4 8192 avgt 3 2.602 ± 0.054 ms/op InflaterOutputStreamWrite.write 4 16384 avgt 3 2.601 ± 0.039 ms/op InflaterOutputStreamWrite.write 4 32768 avgt 3 2.639 ± 0.020 ms/op InflaterOutputStreamWrite.write 4 65536 avgt 3 2.619 ± 0.260 ms/op InflaterOutputStreamWrite.write 8 512 avgt 3 2.882 ± 0.149 ms/op InflaterOutputStreamWrite.write 8 1024 avgt 3 2.695 ± 0.586 ms/op InflaterOutputStreamWrite.write 8 2048 avgt 3 2.644 ± 0.472 ms/op InflaterOutputStreamWrite.write 8 4096 avgt 3 2.616 ± 0.052 ms/op InflaterOutputStreamWrite.write 8 8192 avgt 3 2.616 ± 0.063 ms/op InflaterOutputStreamWrite.write 8 16384 avgt 3 2.611 ± 0.090 ms/op InflaterOutputStreamWrite.write 8 32768 avgt 3 2.633 ± 0.216 ms/op InflaterOutputStreamWrite.write 8 65536 avgt 3 2.634 ± 0.180 ms/op /priv/simonisv/output/jdk-opt-JDK-8242848/images/jdk/bin/java ---------------------------------------------------------------------- Benchmark (scale) (size) Mode Cnt Score Error Units InflaterOutputStreamWrite.write 1 512 avgt 3 5.388 ± 0.349 ms/op InflaterOutputStreamWrite.write 1 1024 avgt 3 3.799 ± 0.093 ms/op InflaterOutputStreamWrite.write 1 2048 avgt 3 2.994 ± 0.023 ms/op InflaterOutputStreamWrite.write 1 4096 avgt 3 2.583 ± 0.159 ms/op InflaterOutputStreamWrite.write 1 8192 avgt 3 2.325 ± 0.345 ms/op InflaterOutputStreamWrite.write 1 16384 avgt 3 2.187 ± 0.126 ms/op InflaterOutputStreamWrite.write 1 32768 avgt 3 2.073 ± 0.083 ms/op InflaterOutputStreamWrite.write 1 65536 avgt 3 2.007 ± 0.153 ms/op InflaterOutputStreamWrite.write 2 512 avgt 3 3.996 ± 0.037 ms/op InflaterOutputStreamWrite.write 2 1024 avgt 3 3.089 ± 0.023 ms/op InflaterOutputStreamWrite.write 2 2048 avgt 3 2.628 ± 0.073 ms/op InflaterOutputStreamWrite.write 2 4096 avgt 3 2.356 ± 0.344 ms/op InflaterOutputStreamWrite.write 2 8192 avgt 3 2.202 ± 0.055 ms/op InflaterOutputStreamWrite.write 2 16384 avgt 3 2.081 ± 0.033 ms/op InflaterOutputStreamWrite.write 2 32768 avgt 3 2.015 ± 0.169 ms/op InflaterOutputStreamWrite.write 2 65536 avgt 3 1.985 ± 0.196 ms/op InflaterOutputStreamWrite.write 4 512 avgt 3 3.325 ± 0.920 ms/op InflaterOutputStreamWrite.write 4 1024 avgt 3 2.740 ± 0.156 ms/op InflaterOutputStreamWrite.write 4 2048 avgt 3 2.415 ± 0.370 ms/op InflaterOutputStreamWrite.write 4 4096 avgt 3 2.250 ± 0.012 ms/op InflaterOutputStreamWrite.write 4 8192 avgt 3 2.115 ± 0.085 ms/op InflaterOutputStreamWrite.write 4 16384 avgt 3 2.042 ± 0.099 ms/op InflaterOutputStreamWrite.write 4 32768 avgt 3 1.988 ± 0.185 ms/op InflaterOutputStreamWrite.write 4 65536 avgt 3 1.975 ± 0.171 ms/op InflaterOutputStreamWrite.write 8 512 avgt 3 2.870 ± 0.035 ms/op InflaterOutputStreamWrite.write 8 1024 avgt 3 2.495 ± 0.334 ms/op InflaterOutputStreamWrite.write 8 2048 avgt 3 2.280 ± 0.056 ms/op InflaterOutputStreamWrite.write 8 4096 avgt 3 2.155 ± 0.073 ms/op InflaterOutputStreamWrite.write 8 8192 avgt 3 2.046 ± 0.079 ms/op InflaterOutputStreamWrite.write 8 16384 avgt 3 1.995 ± 0.098 ms/op InflaterOutputStreamWrite.write 8 32768 avgt 3 1.979 ± 0.119 ms/op InflaterOutputStreamWrite.write 8 65536 avgt 3 1.986 ± 0.155 ms/op > > Thanks, > Laurent > > Le jeu. 23 avr. 2020 à 10:20, Langer, Christoph <[email protected]> a > écrit : >> >> Hi Volker, >> >> since it's not yet pushed, I also went over the change and I like it. +1 >> >> One little style nit caught my eye, which you could correct before pushing: >> The style of the if/else blocks in >> test/jdk/java/util/zip/DeflateIn_InflateOut.java in lines 48/49 and 59/60 >> does not match the other if/else blocks in the file. You should probably >> have the else on the line of the closing bracket before... >> >> Thanks >> Christoph >> >> >> > -----Original Message----- >> > From: core-libs-dev <[email protected]> On Behalf >> > Of Volker Simonis >> > Sent: Mittwoch, 22. April 2020 22:09 >> > To: Lance Andersen <[email protected]> >> > Cc: Java Core Libs <[email protected]>; Vyom Tewari >> > <[email protected]> >> > Subject: Re: RFR(S): 8242848: Improve performance of >> > InflaterOutputStream.write() >> > >> > On Tue, Apr 21, 2020 at 5:23 PM Lance Andersen >> > <[email protected]> wrote: >> > > >> > > Hi Volker, >> > > >> > > I think overall this looks OK. I went through the older SCCS histories >> > > to see >> > if I could figure out why they were using 512 for the input length but >> > could >> > not find anything that might shed some light for me. >> > > >> > >> > Hi Lance, >> > >> > thanks a lot for digging in the old sources to review my change. It's >> > great that we stil have people who can use SCCS :) >> > >> > > I am not sure you can guarantee that src.zip exists but others might be >> > > able >> > to weigh in here. What we have been trying to do going forward is to have >> > the tests create the zip files that it needs. In some cases, we have >> > created a >> > byte array within the test which represents the zip and just write it out >> > before the test begins. >> > > >> > >> > Yes, the dependency on an external file was not nice, so I rewrote the >> > benchmark to programmatically create a file which can be compressed by >> > a factor of ~6: >> > >> > http://cr.openjdk.java.net/~simonis/webrevs/2020/8242848.02/ >> > >> > Notice that this new version only changes the microbenchmark, all the >> > other files are untouched. >> > >> > As everybody seemed to be happy with the change itself and the >> > regression test, I'm now waiting for your and Clae's final review of >> > the microbenchmark before pushing. Please let me know hat you think? >> > >> > Best regards, >> > Volker >> > >> > > I am hoping others with more history might also chime in case they are >> > aware of the history here. >> > > >> > > Thank you for helping improve the performance. >> > > >> > > Best >> > > Lance >> > > >> > > On Apr 17, 2020, at 6:49 AM, Volker Simonis <[email protected]> >> > wrote: >> > > >> > > Thanks everybody for looking at this change! >> > > >> > > Please find an updated webrev (with a new test and micro-benchmark) >> > > and my answers to your comments below: >> > > >> > > http://cr.openjdk.java.net/~simonis/webrevs/2020/8242848.01/ >> > > >> > > On Thu, Apr 16, 2020 at 6:40 AM Vyom Tiwari <[email protected]> >> > wrote: >> > > >> > > Thanks for doing this, i think the below code change is not required . >> > > >> > > Please do let me know if i am not reading it correctly. >> > > >> > > if (inf.finished() || (len == 0)/* no more input */) { >> > > >> > > If you check the native code "inf.finished() will be true only of the >> > corresponding native call inflate(strm, Z_PARTIAL_FLUSH) returns >> > "Z_STREAM_END". >> > > >> > > After your code change write may return even if finished() is not true. >> > > >> > > >> > > Yes, that's true, but that's what we must do if there's no more input >> > > available. Before my change this break on "len < 1" was in the "if >> > > (inf.needsInput())" branch. >> > > >> > > On Thu, Apr 16, 2020 at 8:22 AM Thomas Stüfe >> > <[email protected]> wrote: >> > > >> > > 252 // Check the decompressor >> > > 253 if (inf.finished() || (len == 0)/* no more input */) >> > > { >> > > 254 break; >> > > 255 } >> > > >> > > Not sure but I think this is wrong because now you bypass the followup >> > handling of inf.needsDirectory. >> > > >> > > Inflater.inflate() returns 0 if either needsInput or needsDirectory. We >> > > have >> > to ignore needsInput since we have no input anymore, but needsDirectory >> > has to be handled, no? >> > > >> > > >> > > You're absolutely right Thomas. Thanks for catching this! I've moved >> > > the check for "needsDictionary" in front of the "finished() || len == >> > > 0" check. >> > > >> > > Unfortunately there is not very good test coverage for zip with preset >> > > dictionaries (jtreg and submit repo passed without problems). So I >> > > added a new test for this use case to " >> > > test/jdk/java/util/zip/DeflateIn_InflateOut.java". >> > > >> > > On Thu, Apr 16, 2020 at 8:48 AM Thomas Stüfe >> > <[email protected]> wrote: >> > > >> > > >> > > As for increasing the buffer size, it makes sense but IMHO needs a CSR >> > > and >> > a release note. >> > > >> > > >> > > I don't think so. This is an internal, implementation specific setting >> > > which has never been exposed or documented before so I don't see why >> > > we should document it now. But let's discuss this separately in the >> > > corresponding JBS issue (see below). >> > > >> > > On Thu, Apr 16, 2020 at 1:18 PM Claes Redestad >> > > <[email protected]> wrote: >> > > >> > > >> > > Hi Volker, >> > > >> > > On 2020-04-15 19:48, Volker Simonis wrote: >> > > >> > > While doing this change, I've also realized that all the streams in >> > > java.util.zip (i.e. DeflaterInputStream, GZIPInputStream, >> > > GZIPOutputStream, InflaterInputStream, DeflaterOutputStream) use an >> > > internal byte buffer of 512 bytes by default. Looking at the benchmark >> > > attached to JDK-8242864, I think that increasing this default to a >> > > bigger size (e.g. 4096 bytes) will considerably speed up (up to 50%) >> > > read and write operations on these streams when they are created with >> > > the default buffer size. I think the value "512" is a legacy of old >> > > times when memory was more precious:) so I've opened "JDK-8242864: >> > > Increase the default, internal buffer size of the Streams in >> > > java.util.zip" to track that as as separate issue. Do you think it >> > > makes sense to increase that default value? >> > > >> > > >> > > Seems reasonable. 8192 seems to be the buffer size we've been >> > converging >> > > on elsewhere (see InputStream, BufferedInputStream, Files, ..). I also >> > > >> > > >> > > That seems reasonable. Alan commented on the JBS issue so we can >> > > continue the discussion there. >> > > >> > > found an instance of 8096, which is either a typo or a clever >> > > optimization to keep the array + array object header fit snugly within >> > > 8Kb. You chose. :-) >> > > >> > > >> > > I like how you try to be positive :) >> > > >> > > >> > > Thank you and best regards, >> > > Volker >> > > >> > > PS: do you think it makes sense to contribute the benchmark attached >> > > to JDK-8242864 to the code-tools/mh-jdk-microbenchmarks [1] project? >> > > >> > > [1]http://openjdk.java.net/projects/code-tools/jmh-jdk- >> > microbenchmarks/ >> > > >> > > >> > > I'd definitely welcome the micro as part of the patch under >> > > test/micro/org/openjdk/bench/java/util/zip - additionally contributing >> > > >> > > >> > > I knew that "jmh-jdk-microbenchmarks" has been copied to the jdk repo >> > > but somehow I did found "jmh-jdk-microbenchmarks" before looking in >> > > the obvious place :) >> > > >> > > So I've added the benchmark to the patch now. There's one thing I'm >> > > not sure however. The benchmark requires a "big" (several 100k) with >> > > good compression ratio (e.g. a large text file). I've decided to use a >> > > big Java source file from "src.zip" but I'm not sure if "src.zip" is >> > > always available in the jdk images which are used to run the >> > > microbenchmarks. Do you think the test it is fine this way or do you >> > > have a better idea? I saw that "ZipFind" uses "microbenchmarks.jar" >> > > (i.e. the container of the test itself) but that file is already >> > > compressed so the compression rate won't be that good. >> > > >> > > Another thing I couldn't figure out is a good way to skip the >> > > benchmark when I realize that I can't load the expected file in the >> > > "@Setup" method. Do you now anything better than just throwing an >> > > exception? >> > > >> > > Thank you and best regards, >> > > Volker >> > > >> > > to jmh-jdk-microbenchmarks could enable you to test the micro on 8 or >> > > 11. >> > > >> > > /Claes >> > > >> > > >> > > >> > > Lance Andersen| Principal Member of Technical Staff | +1.781.442.2037 >> > > Oracle Java Engineering >> > > 1 Network Drive >> > > Burlington, MA 01803 >> > > [email protected] >> > > >> > > >> > >
