Ubuntu 11.10下解決 jmap等jdk工具attach pid錯誤

1.錯誤案例

1. www.linuxidc.com@Ubuntu:~/Downloads$ jmap -heap 3991
2. Attaching to process ID 3991, please wait...
3. Error attaching to process: sun.jvm.hotspot.debugger.DebuggerException: Can't attach to the process

2.解決方案

1）修改/etc/sysctl.d/10-ptrace.conf文件如下：

< kernel.yama.ptrace_scope = 1 --- > kernel.yama.ptrace_scope = 0
（即將1改成0）

2）重啟

3.成功

www.linuxidc.com@ubuntu:~$ jmap -heap 1835  
Attaching to process ID 1835, please wait...  
Debugger attached successfully.  
Client compiler detected.  
JVM version is 20.0-b11  
  
using thread-local object allocation.  
Mark Sweep Compact GC  
  
Heap Configuration:  
   MinHeapFreeRatio = 40  
   MaxHeapFreeRatio = 70  
   MaxHeapSize      = 402653184 (384.0MB)  
   NewSize          = 1048576 (1.0MB)  
   MaxNewSize       = 4294901760 (4095.9375MB)  
   OldSize          = 4194304 (4.0MB)  
   NewRatio         = 2  
   SurvivorRatio    = 8  
   PermSize         = 12582912 (12.0MB)  
   MaxPermSize      = 268435456 (256.0MB)  
  
Heap Usage:  
New Generation (Eden + 1 Survivor Space):  
   capacity = 13697024 (13.0625MB)  
   used     = 6592008 (6.286628723144531MB)  
   free     = 7105016 (6.775871276855469MB)  
   48.12730122981459% used  
Eden Space:  
   capacity = 12189696 (11.625MB)  
   used     = 6592008 (6.286628723144531MB)  
   free     = 5597688 (5.338371276855469MB)  
   54.07852665070565% used  
From Space:  
   capacity = 1507328 (1.4375MB)  
   used     = 0 (0.0MB)  
   free     = 1507328 (1.4375MB)  
   0.0% used  
To Space:  
   capacity = 1507328 (1.4375MB)  
   used     = 0 (0.0MB)  
   free     = 1507328 (1.4375MB)  
   0.0% used  
tenured generation:  
   capacity = 30273536 (28.87109375MB)  
   used     = 18162752 (17.32135009765625MB)  
   free     = 12110784 (11.54974365234375MB)  
   59.995475916655394% used  
Perm Generation:  
   capacity = 38273024 (36.5MB)  
   used     = 38107752 (36.342384338378906MB)  
   free     = 165272 (0.15761566162109375MB)  
   99.56817626953125% used