erts: Update +IOt and msacc docs

5 files changed, 20 insertions, 7 deletions

diff --git a/erts/doc/src/erl.xml b/erts/doc/src/erl.xml
index dc58cdeb13..6f6eca2a0b 100644
--- a/erts/doc/src/erl.xml
+++ b/erts/doc/src/erl.xml
@@ -776,6 +776,10 @@
         <p>Sets the number of IO poll threads to use when polling for I/O.
           The maximum number of poll threads allowed is 1024. The default is 1.
         </p>
+        <p>A good way to check if more IO poll threads are needed is to use
+          <seealso marker="runtime_tools:msacc">microstate accounting</seealso>
+          and see what the load of the IO poll thread is. If it is high it could
+          be a good idea to add more threads.</p>
       </item>
       <tag><marker id="+IOPp"/><c>+IOPp PollSetsPercentage</c></tag>
       <item>
@@ -789,7 +793,7 @@
       <item>
         <p>Similar to <seealso marker="#+IOt"><c>+IOt</c></seealso> but uses
           percentages to set the number of IO poll threads to create, based on
-          the number of schedulers configures. If both <c>+IOPt</c> and
+          the number of schedulers configured. If both <c>+IOPt</c> and
           <c>+IOt</c> are used, <c>+IOPt</c> is ignored.
         </p>
       </item>
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index 48aac15827..0a2852b895 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -6456,17 +6456,24 @@ lists:map(
         <p><c><anno>MSAcc_Thread_Type</anno></c>s:</p>
         <taglist>
           <tag><c>scheduler</c></tag>
-          <item>The main execution threads that do most of the work.</item>
+          <item>The main execution threads that do most of the work. See
+            <seealso marker="erts:erl#+S">erl +S</seealso> for more details.</item>
           <tag><c>dirty_cpu_scheduler</c></tag>
-          <item>The threads for long running cpu intensive work.</item>
+          <item>The threads for long running cpu intensive work. See
+            <seealso marker="erts:erl#+SDcpu">erl +SDcpu</seealso> for more details.</item>
           <tag><c>dirty_io_scheduler</c></tag>
-          <item>The threads for long running I/O work.</item>
+          <item>The threads for long running I/O work. See
+            <seealso marker="erts:erl#+SDio">erl +SDio</seealso> for more details.</item>
           <tag><c>async</c></tag>
           <item>Async threads are used by various linked-in drivers (mainly the
-            file drivers) do offload non-CPU intensive work.</item>
+            file drivers) do offload non-CPU intensive work. See
+            <seealso marker="erts:erl#+async_thread_pool_size">erl +A</seealso> for more details.</item>
           <tag><c>aux</c></tag>
           <item>Takes care of any work that is not
             specifically assigned to a scheduler.</item>
+          <tag><c>poll</c></tag>
+          <item>Does the IO polling for the emulator. See
+            <seealso marker="erts:erl#+IOt">erl +IOt</seealso> for more details.</item>
         </taglist>
         <p>The following <c><anno>MSAcc_Thread_State</anno></c>s are available.
           All states are exclusive, meaning that a thread cannot be in two
diff --git a/erts/preloaded/ebin/erlang.beam b/erts/preloaded/ebin/erlang.beam
index e258ff5480..452f3dcc07 100644
--- a/erts/preloaded/ebin/erlang.beam
+++ b/erts/preloaded/ebin/erlang.beam
diff --git a/erts/preloaded/src/erlang.erl b/erts/preloaded/src/erlang.erl
index d43fdc454c..c6c105d36a 100644
--- a/erts/preloaded/src/erlang.erl
+++ b/erts/preloaded/src/erlang.erl
@@ -2344,7 +2344,8 @@ spawn_opt(_Tuple) ->
       MSAcc_Thread :: #{ type := MSAcc_Thread_Type,
                         id := MSAcc_Thread_Id,
                         counters := MSAcc_Counters},
-      MSAcc_Thread_Type :: scheduler | async | aux,
+      MSAcc_Thread_Type :: async | aux | dirty_io_scheduler
+                         | dirty_cpu_scheduler | poll | scheduler,
       MSAcc_Thread_Id :: non_neg_integer(),
       MSAcc_Counters :: #{ MSAcc_Thread_State => non_neg_integer() },
       MSAcc_Thread_State :: alloc | aux | bif | busy_wait | check_io |
diff --git a/lib/runtime_tools/src/msacc.erl b/lib/runtime_tools/src/msacc.erl
index 0d9b2690e5..37887cee72 100644
--- a/lib/runtime_tools/src/msacc.erl
+++ b/lib/runtime_tools/src/msacc.erl
@@ -46,7 +46,8 @@
                                                        system := float()}}.
 
 
--type msacc_type() :: scheduler | aux | async.
+-type msacc_type() :: aux | async | dirty_cpu_scheduler
+                    | dirty_io_scheduler | poll | scheduler.
 -type msacc_id() :: non_neg_integer().
 -type msacc_state() :: alloc | aux | bif | busy_wait | check_io |
                        emulator | ets | gc | gc_fullsweep | nif |