如何定位死循环或高CPU利用率linux

找出调用栈使用gdb attach nmsagent所在的进程,在gdb中使用 info threads显示所有线程gdb gdb>attach 2907gdb>info threads得到如下结果,可以发现2909线程的编号是1213 Thread 0xad5f2b70 (LWP 2908) 0x004ef0d7 in mq_timedreceive () from /lib/tls/i686/cmov/librt.so.112 Thread 0xad58eb70 (LWP 2909) 0x006e0422 in __kernel_vsyscall ()11 Thread 0xad52ab70 (LWP 2910) 0x006e0422 in __kernel_vsyscall ()10 Thread 0xad4f8b70 (LWP 2911) 0x006e0422 in __kernel_vsyscall ()9 Thread 0xad4c6b70 (LWP 2912) 0x006e0422 in __kernel_vsyscall ()8 Thread 0xad3feb70 (LWP 2913) 0x004ef0d7 in mq_timedreceive () from /lib/tls/i686/cmov/librt.so.17 Thread 0xace08b70 (LWP 2914) 0x004ef0d7 in mq_timedreceive () from /lib/tls/i686/cmov/librt.so.16 Thread 0xac607b70 (LWP 2915) 0x006e0422 in __kernel_vsyscall ()5 Thread 0xac5e6b70 (LWP 2916) 0x006e0422 in __kernel_vsyscall ()4 Thread 0xac361b70 (LWP 2917) 0x006e0422 in __kernel_vsyscall ()3 Thread 0xac2fdb70 (LWP 2918) 0x006e0422 in __kernel_vsyscall ()2 Thread 0xac1fcb70 (LWP 2919) 0x004ef0d7 in mq_timedreceive () from /lib/tls/i686/cmov/librt.so.1* 1 Thread 0xb78496d0 (LWP 2907) 0x006e0422 in __kernel_vsyscall ()使用thread 切换线程,使用bt显示线程栈gdb>thread 12 gdb>bt得到如下线程栈#0 0x006e0422 in __kernel_vsyscall ()#1 0x001cca26 in nanosleep () from /lib/tls/i686/cmov/libc.so.6#2 0x001fc2dc in usleep () from /lib/tls/i686/cmov/libc.so.6#3 0x0806b510 in OspTaskDelay ()#4 0x0805c710 in CDispatchTask::NodeMsgSendToSock() ()#5 0x0805cc74 in DispatchTaskEntry ()#6 0x0806a8e9 in OspTaskTemplateFunc(void*) ()#7 0x00d4780e in start_thread () from /lib/tls/i686/cmov/libpthread.so.0#8 0x002027ee in clone () from /lib/tls/i686/cmov/libc.so.6 ps + strace 得到进程ID 21465 ps -e grep cmu 4996 ? 00:00:25 cmu_fjga_sp3 21465 pts/5 00:08:10 cmu得到线程时间, 其中最占CPU的是 EpollRecvTask 21581ps -eL grep 2146521465 21579 pts/5 00:00:00 CamApp21465 21580 pts/5 00:00:00 TimerMan Task21465 21581 pts/5 00:09:02 EpollRecvTask21465 21582 pts/5 00:00:00使用 strace -p 21581 得到线程栈

linux死循环退出方法如下：

1、break语句用于跳出linux死循环。continue用于跳过循环中的一个迭代。break语句可用于跳出循环。

2、break语句跳出循环后，会继续执行该循环之后的代码(如果有的话)：continue语句中断循环中的迭代，如果出现了指定的条件，然后继续循环中的下一个迭代。

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