IT15386: ASSERT FAILED: YIELD_PROCESSOR: CONDITIONAL LATCH COUNT NON-ZERO WHEN LOCK TABLE DYNAMICALLY GROWS AND ALRM_ALL_EVENTS SET TO 1

APAR status

• Closed as fixed if next.

Error description

• This problem only happens on Windows.  The above assertion will
  be seen if the number of cpus configured is set to 1.  If the
  server has > 1 cpu vp, then a server hang can be the result as
  the owner of a spin lock will yield, allowing other threads to
  run, and if the other threads that run attempt to grab the spin
  lock, the owner of the spin lock will not be able to run to
  release it (because all the threads attempting to acquire the
  spin lock do not give up the cpu vp).
  
  The stack trace in the af file is this (as in theory multiple
  database actions could cause the lock table to grow, the only
  relevant portion of the stack is the frames above lkmanagex)
  
  (oninit)afhandler
  (oninit)afcrash_interface
  (oninit)yield_processor_svp
  (oninit)mt_yield
  (oninit)mt_system
  (oninit)invoke_alarmf
  (oninit)mt_sysmsg_body
  (oninit)lkgrow
  (oninit)lkalloc
  (oninit)lkmanagex
  (oninit)lkrow
  (oninit)allocslot
  (oninit)alloc_lastpage
  (oninit)allocvrow
  (oninit)wrt_home
  (oninit)wrtrecord
  (oninit)rswrite
  (oninit)fmwrite
  (oninit)aud_sqiswrite
  (oninit)chkrowcons
  (oninit)addone
  (oninit)ins1row
  (oninit)insone_next
  (oninit)doinsert
  (oninit)sq_putinsert
  (oninit)sqmain
  
  
  With multiple cpu vps and a server hang, what would be seen is a
  non-running thread (would likely be in a ready state) with a
  stack like this:
  
  Stack for thread: 51 sqlexec
   base: 0x0000000084868000
    len:   167936
     pc: 0x0000000140e06b1f
    tos: 0x000000008488d6e0
  state: ready
     vp: 8
  
  NT_yield_processor_mvp ()
  mt_yield ()
  mt_system ()
  invoke_alarmf ()
  mt_sysmsg_body ()
  lkgrow ()
  lkalloc ()
  lkmanagex ()
  lkitem ()
  btnexlock ()
  btadditem ()
  rsbtadditem ()
  isbtadditem ()
  fm_idxinsert ()
  fmwrite (2, 845ddb80, 848a4b00, 840f5d74)
  aud_sqiswrite ()
  chkrowcons ()
  addone ()
  ins1row ()
  insone_next ()
  doinsert ()
  sq_putinsert ()
  sqmain ()
  
  And then 1 or more threads running on other cpu vps that are
  then spinning on spin lock call from lkalloc like this (these
  stacks since the threads are running has to be captured with the
  onmode -X s command)
  
  14:48:54  Stack for thread: 48 dbScheduler
  
   base: 0x000000008443f000
    len:   135168
     pc: 0x0000000140e40318
    tos: 0x000000008445ce40
  state: running
     vp: 8
  
  (oninit)afstack_dump
  (oninit)notifyvp_signal_handler
  (oninit)mt_nap
  (oninit)mt_spin_lock_wait
  (oninit)mt_fast_lock
  (oninit)lkalloc
  (oninit)lkmanagex
  (oninit)lktable
  (oninit)lkrow
  (oninit)gather_records
  (oninit)rsread
  (oninit)fmread
  (oninit)readidx_old
  (oninit)gettupl
  (oninit)scan_next
  (oninit)dodelupd
  (oninit)excommand
  (oninit)sq_execute
  (oninit)mi_exec_prepared_statement
  (oninit)ph_task_lock
  (oninit)ph_get_next_task
  (oninit)db_sched
  (oninit)udrlm_clang_execute_internal
  (oninit)udrlm_clang_execute
  (oninit)udrlm_exec_routine
  (oninit)udr_execute
  (oninit)dbsched_start_udr
  (oninit)th_init_initgls
  (oninit)startup
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * Windows users with ALRM_ALL_EVENTS enabled.                  *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * See Error Description                                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Upgrade to IDS 12.10.FC7 when available.                     *
  ****************************************************************
  

Problem conclusion

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

Applicable component levels

• RB10 PSN

     UP

• RB10 PSY

     UP