Improved scheduler suspend functionality

- The calling process is now suspended while synchronizing
  scheduler suspends via erlang:system_flag(schedulers_online, _)
  and erlang:system_flag(multi_scheduling, _), instead of blocking
  the scheduler thread in the BIF call waiting for the operation
  to synchronize. Besides releasing the scheduler for other work
  (or immediate suspend) it also makes it possible to abort the
  operation by killing the process.
- erlang:system_flag(schedulers_online, _) now only wait for normal
  schedulers to complete before it returns. This since it may take
  a very long time before all dirty schedulers suspends.
- erlang:system_flag(multi_scheduling, block_normal|unblock_normal)
  which only operate on normal schedulers has been introduced. This
  since there are use cases where suspend of dirty schedulers are
  not of interest (hipe loader).
- erlang:system_flag(multi_scheduling, block) still blocks all
  dirty schedulers as well as all normal schedulers except one since
  it is hard to redefine what multi scheduling block means.
- The three operations:
  - changing amount of schedulers online
  - blocking/unblocking normal multi scheduling
  - blocking/unblocking full multi scheduling
  can now be done in parallel. This is important since otherwise
  a full multi scheduling block would potentially delay the other
  operations for a very long time.

1 files changed, 11 insertions, 15 deletions

diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index 6b370e630e..c88bd7056c 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -79,10 +79,8 @@ struct ErtsNodesMonitor_;
 #define ERTS_HAVE_SCHED_UTIL_BALANCING_SUPPORT		0
 
 #define ERTS_MAX_NO_OF_SCHEDULERS 1024
-#ifdef ERTS_DIRTY_SCHEDULERS
 #define ERTS_MAX_NO_OF_DIRTY_CPU_SCHEDULERS ERTS_MAX_NO_OF_SCHEDULERS
 #define ERTS_MAX_NO_OF_DIRTY_IO_SCHEDULERS ERTS_MAX_NO_OF_SCHEDULERS
-#endif
 
 #define ERTS_DEFAULT_MAX_PROCESSES (1 << 18)
 
@@ -246,7 +244,9 @@ extern int erts_sched_thread_suggested_stack_size;
 
 typedef enum {
     ERTS_SCHDLR_SSPND_DONE_MSCHED_BLOCKED,
+    ERTS_SCHDLR_SSPND_DONE_NMSCHED_BLOCKED,
     ERTS_SCHDLR_SSPND_YIELD_DONE_MSCHED_BLOCKED,
+    ERTS_SCHDLR_SSPND_YIELD_DONE_NMSCHED_BLOCKED,
     ERTS_SCHDLR_SSPND_DONE,
     ERTS_SCHDLR_SSPND_YIELD_RESTART,
     ERTS_SCHDLR_SSPND_YIELD_DONE,
@@ -1339,6 +1339,8 @@ extern int erts_system_profile_ts_type;
 #define F_OFF_HEAP_MSGQ_CHNG (1 << 14) /* Off heap msg queue changing */
 #define F_ABANDONED_HEAP_USE (1 << 15) /* Have usage of abandoned heap */
 #define F_DELAY_GC           (1 << 16) /* Similar to disable GC (see below) */
+#define F_SCHDLR_ONLN_WAITQ  (1 << 17) /* Process enqueued waiting to change schedulers online */
+#define F_HAVE_BLCKD_NMSCHED (1 << 18) /* Process has blocked normal multi-scheduling */
 
 /*
  * F_DISABLE_GC and F_DELAY_GC are similar. Both will prevent
@@ -1533,6 +1535,7 @@ int erts_setup_nif_gc(Process* proc, Eterm** objv, int* nobj); /* see erl_nif.c
 void erts_destroy_nif_export(void *); /* see erl_nif.c */
 
 ErtsProcList *erts_proclist_create(Process *);
+ErtsProcList *erts_proclist_copy(ErtsProcList *);
 void erts_proclist_destroy(ErtsProcList *);
 
 ERTS_GLB_INLINE int erts_proclist_same(ErtsProcList *, Process *);
@@ -1718,28 +1721,21 @@ void erts_schedule_complete_off_heap_message_queue_change(Eterm pid);
 #if defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK)
 int erts_dbg_check_halloc_lock(Process *p);
 #endif
-#ifdef DEBUG
-void erts_dbg_multi_scheduling_return_trap(Process *, Eterm);
-#endif
-int erts_get_max_no_executing_schedulers(void);
 #if defined(ERTS_SMP) || defined(ERTS_DIRTY_SCHEDULERS)
-ErtsSchedSuspendResult
-erts_schedulers_state(Uint *, Uint *, Uint *, Uint *, Uint *, Uint *, int);
+void
+erts_schedulers_state(Uint *, Uint *, Uint *, Uint *, Uint *, Uint *, Uint *, Uint *);
 #endif
 #ifdef ERTS_SMP
 ErtsSchedSuspendResult
 erts_set_schedulers_online(Process *p,
 			   ErtsProcLocks plocks,
 			   Sint new_no,
-			   Sint *old_no
-#ifdef ERTS_DIRTY_SCHEDULERS
-			   , int dirty_only
-#endif
-			   );
+			   Sint *old_no,
+			   int dirty_only);
 ErtsSchedSuspendResult
-erts_block_multi_scheduling(Process *, ErtsProcLocks, int, int);
+erts_block_multi_scheduling(Process *, ErtsProcLocks, int, int, int);
 int erts_is_multi_scheduling_blocked(void);
-Eterm erts_multi_scheduling_blockers(Process *);
+Eterm erts_multi_scheduling_blockers(Process *, int);
 void erts_start_schedulers(void);
 void erts_alloc_notify_delayed_dealloc(int);
 void erts_alloc_ensure_handle_delayed_dealloc_call(int);