pstack命令可显示每个进程的栈跟踪。pstack 命令必须由相应进程的属主或 root 运行。可以使用 pstack 来确定进程挂起的位置。此命令允许使用的唯一选项是要检查的进程的 PID。
命令软件包下载地址：https://packages.debian.org/sid/pstack
#### 实例
pstree以树结构显示进程
pstree -p work | grep ad
sshd(22669)---bash(22670)---ad_preprocess(4551)-+-{ad_preprocess}(4552)
|-{ad_preprocess}(4553)
|-{ad_preprocess}(4554)
|-{ad_preprocess}(4555)
|-{ad_preprocess}(4556)
`-{ad_preprocess}(4557)
work为工作用户，-p为显示进程识别码，ad_preprocess共启动了6个子线程，加上主线程共7个线程。
ps -Lf 4551
UID PID PPID LWP C NLWP STIME TTY stat time CMD
work 4551 22670 4551 2 7 16:30 pts/2 Sl+ 0:02 ./ad_preprocess
work 4551 22670 4552 0 7 16:30 pts/2 Sl+ 0:00 ./ad_preprocess
work 4551 22670 4553 0 7 16:30 pts/2 Sl+ 0:00 ./ad_preprocess
work 4551 22670 4554 0 7 16:30 pts/2 Sl+ 0:00 ./ad_preprocess
work 4551 22670 4555 0 7 16:30 pts/2 Sl+ 0:00 ./ad_preprocess
work 4551 22670 4556 0 7 16:30 pts/2 Sl+ 0:00 ./ad_preprocess
work 4551 22670 4557 0 7 16:30 pts/2 Sl+ 0:00 ./ad_preprocess
进程共启动了7个线程
pstack显示每个进程的栈跟踪：
pstack 4551
Thread 7 (Thread 1084229984 (LWP 4552)):
#0 0x000000302afc63dc in epoll_wait () from /lib64/tls/libc.so.6
#1 0x00000000006f0730 in ub::EPollEx::poll ()
#2 0x00000000006f172a in ub::NetReactor::callback ()
#3 0x00000000006fbbbb in ub::UBTask::CALLBACK ()
#4 0x000000302b80610a in start_thread () from /lib64/tls/libpthread.so.0
#5 0x000000302afc6003 in clone () from /lib64/tls/libc.so.6
#6 0x0000000000000000 in ?? ()
Thread 6 (Thread 1094719840 (LWP 4553)):
#0 0x000000302afc63dc in epoll_wait () from /lib64/tls/libc.so.6
#1 0x00000000006f0730 in ub::EPollEx::poll ()
#2 0x00000000006f172a in ub::NetReactor::callback ()
#3 0x00000000006fbbbb in ub::UBTask::CALLBACK ()
#4 0x000000302b80610a in start_thread () from /lib64/tls/libpthread.so.0
#5 0x000000302afc6003 in clone () from /lib64/tls/libc.so.6
#6 0x0000000000000000 in ?? ()
Thread 5 (Thread 1105209696 (LWP 4554)):
#0 0x000000302b80baa5 in __nanosleep_nocancel ()
#1 0x000000000079e758 in comcm::ms_sleep ()
#2 0x00000000006c8581 in ub::UbClientManager::healthyCheck ()
#3 0x00000000006c8471 in ub::UbClientManager::start_healthy_check ()
#4 0x000000302b80610a in start_thread () from /lib64/tls/libpthread.so.0
#5 0x000000302afc6003 in clone () from /lib64/tls/libc.so.6
#6 0x0000000000000000 in ?? ()
Thread 4 (Thread 1115699552 (LWP 4555)):
#0 0x000000302b80baa5 in __nanosleep_nocancel ()
#1 0x0000000000482b0e in armor::armor_check_thread ()
#2 0x000000302b80610a in start_thread () from /lib64/tls/libpthread.so.0
#3 0x000000302afc6003 in clone () from /lib64/tls/libc.so.6
#4 0x0000000000000000 in ?? ()
Thread 3 (Thread 1126189408 (LWP 4556)):
#0 0x000000302af8f1a5 in __nanosleep_nocancel () from /lib64/tls/libc.so.6
#1 0x000000302af8f010 in sleep () from /lib64/tls/libc.so.6
#2 0x000000000044c972 in Business_config_manager::run ()
#3 0x0000000000457b83 in Thread::run_thread ()
#4 0x000000302b80610a in start_thread () from /lib64/tls/libpthread.so.0
#5 0x000000302afc6003 in clone () from /lib64/tls/libc.so.6
#6 0x0000000000000000 in ?? ()
Thread 2 (Thread 1136679264 (LWP 4557)):
#0 0x000000302af8f1a5 in __nanosleep_nocancel () from /lib64/tls/libc.so.6
#1 0x000000302af8f010 in sleep () from /lib64/tls/libc.so.6
#2 0x00000000004524bb in Process_thread::sleep_period ()
#3 0x0000000000452641 in Process_thread::run ()
#4 0x0000000000457b83 in Thread::run_thread ()
#5 0x000000302b80610a in start_thread () from /lib64/tls/libpthread.so.0
#6 0x000000302afc6003 in clone () from /lib64/tls/libc.so.6
#7 0x0000000000000000 in ?? ()
Thread 1 (Thread 182894129792 (LWP 4551)):
#0 0x000000302af8f1a5 in __nanosleep_nocancel () from /lib64/tls/libc.so.6
#1 0x000000302af8f010 in sleep () from /lib64/tls/libc.so.6
#2 0x0000000000420d79 in Ad_preprocess::run ()
#3 0x0000000000450ad0 in main ()