Geir Magnusson Jr. wrote: > This is great stuff, but I meant "relative to a week or so ago". IOW, > it feels like we slowed down recently. > > That said, what you have below is great, and certainly will be good > fodder for someone to look into. We should capture it as a ToDo. > > Could you please put an Apache license on the top of the code on your > site? I'm going to make a little JVMTI "how to" and that's a cute bit > of code to use as an example.
Yes!! > > geir > > > Gregory Shimansky wrote: >> Geir Magnusson Jr. wrote: >>> The DRLVM suite... >>> >>> So the question is... was 20-25 min the time you expected? >>> >>> Mikhail Loenko wrote: >>>> which tests did you run? >>>> >>>> I ran Classlib tests on DRLVM in "once" fork mode. it took about >>>> 20-25 minutes >>>> on each x86 and x86_64 on Linux >>>> >>>> 2006/12/9, Geir Magnusson Jr. <[EMAIL PROTECTED]>: >>>>> I've been running tests on x86 and x86_64 linux, and things "feel" >>>>> slow. >>>>> Problem is I don't have any times to compare to - can we add that to >>>>> the data recorded in harmonytest? >>>>> >>>>> Does anyone else feel that things are slow? >> >> I think the worst place in executing tests in "once" mode is >> initialization stage of VM + classlib. I've written a simple JVMTI >> agent which uses JVMTI MethodEntry event [1] just to count called >> classlib methods to execute a Hello world program. The program itself >> is very small, so almost all of the called methods are classlib >> initialization. Also keep in mind that MethodEntry event is sent only >> in LIVE [2] JVMTI phase, this means that classlib bootstrap, and >> classlib shutdown are not included. >> >> After agent is executed, it creates a log of called methods. The >> number of methods which I get is 345718. This is very very many. >> Comparing with Sun JRE, the number of methods they use is 9482. True >> that when drlvm runs in JVMTI mode, it uses only Jitrino.JET, which >> doesn't inline any methods, but on the other hand Sun when running in >> JVMTI mode should report every called method as well. So the >> difference with Sun is 36 times. Agent code is in [3]. On windows >> compile like this: >> >> cl >> -Ic:/work/harmony/enhanced/trunk/working_vm/build/win_ia32_msvc_debug/deploy/jre/include >> -Femethodee.dll -LD methodee.cpp >> >> execute like this: >> >> java -agentpath:methodee.dll Hello >> >> To count methods which agent doesn't see in classlib bootstrap and >> shutdown phases I've created a small patch which adds tracing to drlvm >> to jvmti_method_enter_callback. This function is always called when >> JVMTI registers can_generate_method_entry_events capability. The calls >> to agent are filtered out when phase is not LIVE. Using this patch I >> get all of the methods which are executed. The number in this case is >> 356826. So this gives only 11108 calls in bootstrap and shutdown. The >> number is not very big compared to what is executed in LIVE phase. >> Patch code is in [4]. Add >> >> -Xtrace:jvmti.event.method.entry:log.txt >> >> to the above command line to log tracing to file when running drlvm). >> >> It seems like 99% of all LIVE phase calls are user class loader >> execution. All of those 345k calls are what it takes for Java class >> loader to find Hello world class. Analyzing the log with this script >> >> cat method_entry.log | sort | uniq -c | sort -nr >> >> I've found the top 10 methods which are executed most of the times: >> >> 156382 Ljava/io/ByteArrayOutputStream;.write(I)V >> 19985 Ljava/lang/Object;.<init>()V >> 13927 Ljava/lang/String;.hashCode()I >> 9259 Ljava/lang/Character;.toLowerCase(C)C >> 7807 Ljava/io/ByteArrayOutputStream;.size()I >> 7648 Ljava/lang/String;.<init>(II[C)V >> 6299 >> Ljava/lang/System;.arraycopy(Ljava/lang/Object;ILjava/lang/Object;II)V >> 6219 Ljava/lang/String;.length()I >> 6101 Ljava/lang/String;.substring(II)Ljava/lang/String; >> 6089 Ljava/util/ArrayList;.size()I >> >> the first one is absolute champion. I wonder why it is used to many >> times. It looks like some parts of classlib copy memory byte by byte >> extensively using ByteArrayOutputStream. It is probably a good >> starting place for performance improvement. >> >> >> [1] >> http://java.sun.com/j2se/1.5.0/docs/guide/jvmti/jvmti.html#MethodEntry >> >> [2] http://java.sun.com/j2se/1.5.0/docs/guide/jvmti/jvmti.html#GetPhase >> >> [3] http://people.apache.org/~gshimansky/methodee.cpp >> >> [4] http://people.apache.org/~gshimansky/jvmti.patch >> -- Stefano.
