- Softlockup with pThreads, Mutexes on Haswell CPUs and PowerPC CPUs (but may not be limited to just these)
- After upgrading to Red Hat Enterprise Linux 6.6 (specifically 2.6.32-504 up to and including 2.6.32-504.12.2) may result in an application hang.
- Cannot get a thread dump using
kill -3doesn't respond.
/proc/shows all threads are stuck waiting on a futex. For example:
Where nnnn = the PID # of the parent task in question mmmm = the PID # of the thread task Note. Under the parent /proc/nnnn/task structure you will see the PID's of all of the threads including the parents number repeated. cat /proc/nnnn/task/mmmm/stack [<ffffffff810b226a>] futex_wait_queue_me+0xba/0xf0 [<ffffffff810b33a0>] futex_wait+0x1c0/0x310 [<ffffffff810b4c91>] do_futex+0x121/0xae0 [<ffffffff810b56cb>] sys_futex+0x7b/0x170 [<ffffffff8100b072>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff
stracecauses the application to wake up and continue processing.
- Red Hat Enterprise Linux (RHEL) 6.6, 7.0 and 7.1
Application uses syscall FUTEX with Private Userspace futex locking
- Does not affect Shared or Inode Futex locking
Other possible packages may include:
- IBM JDK 6 32-bit
- Oracle JDK 7 64-bit
Subscriber exclusive content
A Red Hat subscription provides unlimited access to our knowledgebase of over 48,000 articles and solutions.
Welcome! Check out the Getting Started with Red Hat page for quick tours and guides for common tasks.