クライアントアプリケーションがあります(10年以上の開発)。最近、そのJDKがOpenJDK 11からOpenJDK 14にアップグレードされました。シングルCPU(ハイパースレッディングが無効)のWindows 10セットアップ(および使用可能なCPUが1つだけのVirtualBoxマシン内)では、Java 11に比べてアプリケーションの起動が非常に遅くなります。さらに、ほとんどの場合100%のCPUを使用します。プロセッサアフィニティを1つのCPUのみに設定することで問題を再現することもできます(c:\windows\system32\cmd.exe /C start /affinity 1 ...
)。
私のVirtualBoxマシンでアプリケーションを開始し、最小限の手動操作でクエリを実行することによる測定:
- OpenJDK 11.0.2:36秒
- OpenJDK 13.0.2:〜1.5分
- OpenJDK 13.0.2 with
-XX:-UseBiasedLocking
:46秒 - OpenJDK 13.0.2 with
-XX:-ThreadLocalHandshakes
:40秒 - OpenJDK 14:5〜6分
- OpenJDK 14 with
-XX:-UseBiasedLocking
:3-3,5分 - OpenJDK 15 EAビルド20:〜4,5分
使用されているJDK(および上記のオプション)のみが変更されています。(-XX:-ThreadLocalHandshakes
Java 14では使用できません。)
JDK 14で何ができるかをログに記録してみました-Xlog:all=debug:file=app.txt:uptime,tid,level,tags:filecount=50
。
OpenJDK 11.0.2では、毎秒のログ行を数えるのは非常にスムーズに見えます。
$ cat jdk11-log/app* | grep "^\[" | cut -d. -f 1 | cut -d[ -f 2 | sort | uniq -c | sort -k 2 -n
30710 0
44012 1
55461 2
55974 3
27182 4
41292 5
43796 6
51889 7
54170 8
58850 9
51422 10
44378 11
41405 12
53589 13
41696 14
29526 15
2350 16
50228 17
62623 18
42684 19
45045 20
一方、OpenJDK 14には興味深い休止期間があるようです。
$ cat jdk14-log/app* | grep "^\[" | cut -d. -f 1 | cut -d[ -f 2 | sort | uniq -c | sort -k 2 -n
7726 0
1715 5
10744 6
4341 11
42792 12
45979 13
38783 14
17253 21
34747 22
1025 28
2079 33
2398 39
3016 44
では、1〜4秒、7〜10秒、14〜20秒の間に何が起こっているのでしょうか。
...
[0.350s][7248][debug][class,resolve ] jdk.internal.ref.CleanerFactory$1 java.lang.Thread CleanerFactory.java:45
[0.350s][7248][debug][class,resolve ] jdk.internal.ref.CleanerImpl java.lang.Thread CleanerImpl.java:117
[0.350s][7248][info ][biasedlocking ] Aligned thread 0x000000001727e010 to 0x000000001727e800
[0.350s][7248][info ][os,thread ] Thread started (tid: 2944, attributes: stacksize: default, flags: CREATE_SUSPENDED STACK_SIZE_PARAM_IS)
[0.350s][6884][info ][os,thread ] Thread is alive (tid: 6884).
[0.350s][6884][debug][os,thread ] Thread 6884 stack dimensions: 0x00000000175b0000-0x00000000176b0000 (1024k).
[0.350s][6884][debug][os,thread ] Thread 6884 stack guard pages activated: 0x00000000175b0000-0x00000000175b4000.
[0.350s][7248][debug][thread,smr ] tid=7248: Threads::add: new ThreadsList=0x0000000017254500
[0.350s][7248][debug][thread,smr ] tid=7248: ThreadsSMRSupport::free_list: threads=0x0000000017253d50 is freed.
[0.350s][2944][info ][os,thread ] Thread is alive (tid: 2944).
[0.350s][2944][debug][os,thread ] Thread 2944 stack dimensions: 0x00000000177b0000-0x00000000178b0000 (1024k).
[0.350s][2944][debug][os,thread ] Thread 2944 stack guard pages activated: 0x00000000177b0000-0x00000000177b4000.
[0.351s][2944][debug][class,resolve ] java.lang.Thread java.lang.Runnable Thread.java:832
[0.351s][2944][debug][class,resolve ] jdk.internal.ref.CleanerImpl jdk.internal.misc.InnocuousThread CleanerImpl.java:135
[0.351s][2944][debug][class,resolve ] jdk.internal.ref.CleanerImpl jdk.internal.ref.PhantomCleanable CleanerImpl.java:138
[0.351s][2944][info ][biasedlocking,handshake] JavaThread 0x000000001727e800 handshaking JavaThread 0x000000000286d800 to revoke object 0x00000000c0087f78
[0.351s][2944][debug][vmthread ] Adding VM operation: HandshakeOneThread
[0.351s][6708][debug][vmthread ] Evaluating non-safepoint VM operation: HandshakeOneThread
[0.351s][6708][debug][vmoperation ] begin VM_Operation (0x00000000178af250): HandshakeOneThread, mode: no safepoint, requested by thread 0x000000001727e800
# no log until 5.723s
[5.723s][7248][info ][biasedlocking ] Revoked bias of currently-unlocked object
[5.723s][7248][debug][handshake,task ] Operation: RevokeOneBias for thread 0x000000000286d800, is_vm_thread: false, completed in 94800 ns
[5.723s][7248][debug][class,resolve ] java.util.zip.ZipFile$CleanableResource java.lang.ref.Cleaner ZipFile.java:715
[5.723s][7248][debug][class,resolve ] java.lang.ref.Cleaner jdk.internal.ref.CleanerImpl$PhantomCleanableRef Cleaner.java:220
[5.723s][7248][debug][class,resolve ] java.util.zip.ZipFile$CleanableResource java.util.WeakHashMap ZipFile.java:716
...
少し後の2番目の一時停止:
...
[6.246s][7248][info ][class,load ] java.awt.Graphics source: jrt:/java.desktop
[6.246s][7248][debug][class,load ] klass: 0x0000000100081a00 super: 0x0000000100001080 loader: [loader data: 0x0000000002882bd0 of 'bootstrap'] bytes: 5625 checksum: 0025818f
[6.246s][7248][debug][class,resolve ] java.awt.Graphics java.lang.Object (super)
[6.246s][7248][info ][class,loader,constraints] updating constraint for name java/awt/Graphics, loader 'bootstrap', by setting class object
[6.246s][7248][debug][jit,compilation ] 19 4 java.lang.Object::<init> (1 bytes) made not entrant
[6.246s][7248][debug][vmthread ] Adding VM operation: HandshakeAllThreads
[6.246s][6708][debug][vmthread ] Evaluating non-safepoint VM operation: HandshakeAllThreads
[6.246s][6708][debug][vmoperation ] begin VM_Operation (0x000000000203ddf8): HandshakeAllThreads, mode: no safepoint, requested by thread 0x000000000286d800
[6.246s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x00000000026b0800, is_vm_thread: true, completed in 1400 ns
[6.246s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x00000000026bb800, is_vm_thread: true, completed in 700 ns
[6.246s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x00000000026ef800, is_vm_thread: true, completed in 100 ns
[6.246s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x00000000026f0800, is_vm_thread: true, completed in 100 ns
[6.246s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x00000000026f1800, is_vm_thread: true, completed in 100 ns
[6.246s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x00000000026f4800, is_vm_thread: true, completed in 100 ns
[6.247s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x0000000002768800, is_vm_thread: true, completed in 100 ns
[6.247s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x000000000276e000, is_vm_thread: true, completed in 100 ns
[6.247s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x0000000017268800, is_vm_thread: true, completed in 100 ns
[6.247s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x000000001727e800, is_vm_thread: true, completed in 800 ns
# no log until 11.783s
[11.783s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x000000000286d800, is_vm_thread: true, completed in 6300 ns
[11.783s][6708][info ][handshake ] Handshake "Deoptimize", Targeted threads: 11, Executed by targeted threads: 0, Total completion time: 5536442500 ns
[11.783s][6708][debug][vmoperation ] end VM_Operation (0x000000000203ddf8): HandshakeAllThreads, mode: no safepoint, requested by thread 0x000000000286d800
[11.783s][7248][debug][protectiondomain ] Checking package access
[11.783s][7248][debug][protectiondomain ] class loader: a 'jdk/internal/loader/ClassLoaders$AppClassLoader'{0x00000000c0058628} protection domain: a 'java/security/ProtectionDomain'{0x00000000c058b948} loading: 'java/awt/Graphics'
[11.783s][7248][debug][protectiondomain ] granted
[11.783s][7248][debug][class,resolve ] sun.launcher.LauncherHelper java.awt.Graphics LauncherHelper.java:816 (reflection)
[11.783s][7248][debug][class,resolve ] jdk.internal.reflect.Reflection [Ljava.lang.reflect.Method; Reflection.java:300
[11.783s][7248][debug][class,preorder ] java.lang.PublicMethods$MethodList source: C:\Users\example\AppData\Local\example\stable\jdk\lib\modules
...
次に、3番目のもの:
...
[14.578s][7248][debug][class,preorder ] java.lang.InheritableThreadLocal source: C:\Users\example\AppData\Local\example\stable\jdk\lib\modules
[14.578s][7248][info ][class,load ] java.lang.InheritableThreadLocal source: jrt:/java.base
[14.578s][7248][debug][class,load ] klass: 0x0000000100124740 super: 0x0000000100021a18 loader: [loader data: 0x0000000002882bd0 of 'bootstrap'] bytes: 1338 checksum: 8013ed55
[14.578s][7248][debug][class,resolve ] java.lang.InheritableThreadLocal java.lang.ThreadLocal (super)
[14.578s][7248][debug][jit,compilation ] 699 3 java.lang.ThreadLocal::get (38 bytes) made not entrant
[14.578s][7248][debug][vmthread ] Adding VM operation: HandshakeAllThreads
[14.578s][6708][debug][vmthread ] Evaluating non-safepoint VM operation: HandshakeAllThreads
[14.578s][6708][debug][vmoperation ] begin VM_Operation (0x000000000203d228): HandshakeAllThreads, mode: no safepoint, requested by thread 0x000000000286d800
[14.578s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x00000000026b0800, is_vm_thread: true, completed in 1600 ns
[14.578s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x00000000026bb800, is_vm_thread: true, completed in 900 ns
[14.578s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x00000000026ef800, is_vm_thread: true, completed in 100 ns
[14.578s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x00000000026f0800, is_vm_thread: true, completed in 100 ns
[14.578s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x00000000026f1800, is_vm_thread: true, completed in 100 ns
[14.578s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x00000000026f4800, is_vm_thread: true, completed in 0 ns
[14.578s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x0000000002768800, is_vm_thread: true, completed in 0 ns
[14.578s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x000000000276e000, is_vm_thread: true, completed in 0 ns
[14.578s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x0000000017268800, is_vm_thread: true, completed in 0 ns
[14.579s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x000000001727e800, is_vm_thread: true, completed in 900 ns
# no log until 21.455s
[21.455s][6708][debug][handshake,task ] Operation: Deoptimize for thread 0x000000000286d800, is_vm_thread: true, completed in 12100 ns
[21.455s][6708][info ][handshake ] Handshake "Deoptimize", Targeted threads: 11, Executed by targeted threads: 0, Total completion time: 6876829000 ns
[21.455s][6708][debug][vmoperation ] end VM_Operation (0x000000000203d228): HandshakeAllThreads, mode: no safepoint, requested by thread 0x000000000286d800
[21.455s][7248][debug][class,resolve ] sun.security.jca.Providers java.lang.InheritableThreadLocal Providers.java:39
[21.455s][7248][info ][class,init ] 1251 Initializing 'java/lang/InheritableThreadLocal'(no method) (0x0000000100124740)
[21.455s][7248][debug][class,resolve ] java.lang.InheritableThreadLocal java.lang.ThreadLocal InheritableThreadLocal.java:57
[21.456s][7248][debug][class,preorder ] sun.security.jca.ProviderList source: C:\Users\example\AppData\Local\example\stable\jdk\lib\modules
[21.456s][7248][info ][class,load ] sun.security.jca.ProviderList source: jrt:/java.base
[21.456s][7248][debug][class,load ] klass: 0x00000001001249a8 super: 0x0000000100001080 loader: [loader data: 0x0000000002882bd0 of 'bootstrap'] bytes: 11522 checksum: bdc239d2
[21.456s][7248][debug][class,resolve ] sun.security.jca.ProviderList java.lang.Object (super)
...
次の2行は興味深いようです。
[11.783s][6708][info ][handshake ] Handshake "Deoptimize", Targeted threads: 11, Executed by targeted threads: 0, Total completion time: 5536442500 ns
[21.455s][6708][info ][handshake ] Handshake "Deoptimize", Targeted threads: 11, Executed by targeted threads: 0, Total completion time: 6876829000 ns
これらのハンドシェイクに5.5秒と6.8秒かかったのは正常ですか?
このコマンドで実行されているupdate4jデモアプリ(これはアプリケーションとはまったく関係ありません)でも同じ速度低下(および同様のログ)が発生しました。
Z:\swing>\jdk-14\bin\java -Xlog:all=debug:file=app.txt:uptime,tid,level,tags:filecount=50 \
-jar update4j-1.4.5.jar --remote http://docs.update4j.org/demo/setup.xml
シングルCPUのWindows 10セットアップでアプリをより高速にするために何を探す必要がありますか?アプリケーションで何かを変更したり、JVM引数を追加したりして、これを修正できますか?
これはJDKのバグですか、報告する必要がありますか?
2020-04-25の更新:
私が見る限り、ログファイルにはGCログも含まれています。これらは最初のGCログです。
$ cat app.txt.00 | grep "\[gc"
[0.016s][7248][debug][gc,heap ] Minimum heap 8388608 Initial heap 60817408 Maximum heap 1073741824
[0.017s][7248][info ][gc,heap,coops ] Heap address: 0x00000000c0000000, size: 1024 MB, Compressed Oops mode: 32-bit
[0.018s][7248][info ][gc ] Using Serial
[22.863s][6708][info ][gc,start ] GC(0) Pause Young (Allocation Failure)
[22.863s][6708][debug][gc,heap ] GC(0) Heap before GC invocations=0 (full 0): def new generation total 17856K, used 15936K [0x00000000c0000000, 0x00000000c1350000, 0x00000000d5550000)
...
残念ながら、3回目の休止後に開始されるため、関連性がないようです。
2020-04-26の更新:
OpenJDK 14では、アプリケーションは私の(シングルCPU)VirtualBoxマシン(i7-6600U CPUで実行)で100%CPUを使用します。仮想マシンには3.5 GBのRAMがあります。タスクマネージャによると、40%以上は無料で、ディスクアクティビティは0%です(これはスワッピングがないことを意味していると思います)。仮想マシンに別のCPUを追加すると(そして物理マシンのハイパースレッディングを有効にすると)、アプリケーションは再び十分に高速になります。マルチコア/ハイパースレッディングCPUでJVMを高速化するために(まれな)シングルCPUマシンでパフォーマンスを失うことは、JDK開発中に意図的なトレードオフでしたか?
-Xlog:all=debug
GCログを有効に?それは私の一時停止の最初の推測です。