erts: Add the +sfwi system flag

+sfwi Interval
    Set scheduler forced wakeup interval. All run queues will be scanned
    each Interval milliseconds. While there are sleeping schedulers in
    the system, one scheduler will be woken for each non-empty run queue
    found. An Interval of zero disables this feature, which also is the
    default.

    This feature has been introduced as a temporary workaround for lengthy
    executing native code, and native code that do not bump reductions
    properly in OTP. When these bugs have be fixed the +sfwi flag will
    be removed.

Conflicts:

	erts/doc/src/erl.xml
	erts/etc/common/erlexec.c

1 files changed, 4 insertions, 0 deletions

diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index 968971ed4c..9b0e9f1ccd 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -371,6 +371,10 @@ struct ErtsRunQueue_ {
     } ports;
 };
 
+#ifdef ERTS_SMP
+extern long erts_runq_supervision_interval;
+#endif
+
 typedef union {
     ErtsRunQueue runq;
     char align[ERTS_ALC_CACHE_LINE_ALIGN_SIZE(sizeof(ErtsRunQueue))];