.
Thread 2 (process 912):
#0  pthread_cond_wait@@GLIBC_2.3.2 ()
    at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
No locals.
#1  0x0000000000408ce2 in beep_thread (arg=0x6134e0) at beep.c:190
	dsp = (struct dspdata *) 0x6134e0
#2  0x00007fa1d3f7cd8c in start_thread (arg=0x7fa1d035f700)
    at allocatestack.c:304
	pd = (struct pthread *) 0x7fa1d035f700
	now = <value optimized out>
	unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140332959659776, 
        -3600026706638334549, 140735083164992, 140332959660480, 0, 3, 
        3551513419448784299, 3551516184283387307}, mask_was_saved = 0}}, 
  priv = {pad = {0x0, 0x0, 0x0, 0x0}, data = {prev = 0x0, cleanup = 0x0, 
      canceltype = 0}}}
	not_first_call = 0
	robust = <value optimized out>
	sp = <value optimized out>
	freesize = <value optimized out>
	__PRETTY_FUNCTION__ = "start_thread"
#3  0x00007fa1d33b039d in clone ()
    at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
No locals.
#4  0x0000000000000000 in ?? ()
No symbol table info available.
.
Thread 1 (process 910):
#0  0x00007fa1d3cd3b30 in snd_mixer_handle_events (mixer=0xfba3a0)
    at mixer.c:632
	err = <value optimized out>
	s = Unhandled dwarf expression opcode 0x9f
Current language:  auto; currently asm
Current language:  auto; currently c