Merge branch 'rickard/maint-17/eager-check-io/OTP-12117' into rickard/master/eager-check-io/OTP-12117

* rickard/maint-17/eager-check-io/OTP-12117:
  No eager check I/O on OSE
  Introduce support for eager check I/O scheduling

Conflicts:
	erts/preloaded/ebin/erlang.beam

2 files changed, 28 insertions, 0 deletions

diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml
index f856b9ab86..141754e4f9 100644
--- a/erts/doc/src/erl.xml
+++ b/erts/doc/src/erl.xml
@@ -1141,6 +1141,23 @@
 	    <p>For more information, see
 	    <seealso marker="erlang#system_info_cpu_topology">erlang:system_info(cpu_topology)</seealso>.</p>
           </item>
+          <tag><marker id="+secio"><c>+secio true|false</c></marker></tag>
+          <item>
+	    <p>Enable or disable eager check I/O scheduling. The default
+	    is currently <c>false</c>, but will most likely be changed
+	    to <c>true</c> in OTP 18. The behaviour before this flag
+	    was introduced corresponds to <c>+secio false</c>.</p>
+	    <p>The flag effects when schedulers will check for I/O
+	    operations possible to execute, and when such I/O operations
+	    will execute. As the name of the parameter implies,
+	    schedulers will be more eager to check for I/O when
+	    <c>true</c> is passed. This however also implies that
+	    execution of outstanding I/O operation will not be
+	    prioritized to the same extent as when <c>false</c> is
+	    passed.</p>
+	    <p><seealso marker="erlang#system_info_eager_check_io"><c>erlang:system_info(eager_check_io)</c></seealso>
+	    returns the value of this parameter used when starting the VM.</p>
+          </item>
           <tag><marker id="+sfwi"><c>+sfwi Interval</c></marker></tag>
           <item>
             <p>Set scheduler forced wakeup interval. All run queues will
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index 97fe6d2915..226f2c0150 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -5789,6 +5789,7 @@ ok
       <name name="system_info" arity="1" clause_i="52"/>
       <name name="system_info" arity="1" clause_i="53"/>
       <name name="system_info" arity="1" clause_i="54"/>
+      <name name="system_info" arity="1" clause_i="55"/>
       <fsummary>Information about the system</fsummary>
       <desc>
         <p>Returns various information about the current system
@@ -5984,6 +5985,16 @@ ok
 	      The return value will always be <c>false</c> since
 	      the elib_malloc allocator has been removed.</p>
           </item>
+          <tag><marker id="system_info_eager_check_io"><c>eager_check_io</c></marker></tag>
+          <item>
+            <p>
+	      Returns the value of the <c>erl</c>
+	      <seealso marker="erl#+secio">+secio</seealso> command line
+	      flag which is either <c>true</c> or <c>false</c>. See the
+	      documentation of the command line flag for information about
+	      the different values.
+	    </p>
+          </item>
           <tag><c>ets_limit</c></tag>
           <item>
             <p>Returns the maximum number of ETS tables allowed. This limit