From c7dc896e8897988ccc033e18fa19670ba7160565 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?John=20H=C3=B6gberg?= <john@erlang.org>
Date: Thu, 3 May 2018 12:37:49 +0200
Subject: Allow cross-type carrier migration

---
 lib/tools/doc/src/instrument.xml    | 13 ++++++++-----
 lib/tools/test/instrument_SUITE.erl | 30 ++++++++++++++++++++++++------
 2 files changed, 32 insertions(+), 11 deletions(-)

(limited to 'lib')

diff --git a/lib/tools/doc/src/instrument.xml b/lib/tools/doc/src/instrument.xml
index 9fd9332373..79bacb2927 100644
--- a/lib/tools/doc/src/instrument.xml
+++ b/lib/tools/doc/src/instrument.xml
@@ -111,15 +111,18 @@
           default, but this can be configured an a per-allocator basis with the
           <seealso marker="erts:erts_alloc#M_atags"><c>+M&lt;S&gt;atags</c>
           </seealso> emulator option.</p>
-        <p>If tagged allocations are not enabled on any of the specified
-          allocator types, the call will fail with
-          <c>{error, not_enabled}</c>.</p>
+        <p>If the specified allocator types are not enabled, the call will fail
+          with <c>{error, not_enabled}</c>.</p>
         <p>The following options can be used:</p>
         <taglist>
           <tag><c>allocator_types</c></tag>
           <item>
-            <p>The allocator types that will be searched. Defaults to all
-              <c>alloc_util</c> allocators.</p>
+            <p>The allocator types that will be searched. Note that blocks can
+              move freely between allocator types, so restricting the search to
+              certain allocators may return unexpected types (e.g. process
+              heaps when searching binary_alloc), or hide blocks that were
+              migrated out.</p>
+            <p>Defaults to all <c>alloc_util</c> allocators.</p>
           </item>
           <tag><c>scheduler_ids</c></tag>
           <item>
diff --git a/lib/tools/test/instrument_SUITE.erl b/lib/tools/test/instrument_SUITE.erl
index 8c521b2e1a..33800c5934 100644
--- a/lib/tools/test/instrument_SUITE.erl
+++ b/lib/tools/test/instrument_SUITE.erl
@@ -77,6 +77,8 @@ allocations_ramv(Config) when is_list(Config) ->
 verify_allocations_disabled(_AllocType, Result) ->
     verify_allocations_disabled(Result).
 
+verify_allocations_disabled({ok, {_HistStart, _UnscannedBytes, Allocs}}) ->
+    true = Allocs =:= #{};
 verify_allocations_disabled({error, not_enabled}) ->
     ok.
 
@@ -91,6 +93,13 @@ verify_allocations_enabled(_AllocType, Result) ->
 verify_allocations_enabled({ok, {_HistStart, _UnscannedBytes, Allocs}}) ->
     true = Allocs =/= #{}.
 
+verify_allocations_output(#{}, {ok, {_, _, Allocs}}) when Allocs =:= #{} ->
+    %% This happens when the allocator is enabled but tagging is disabled. If
+    %% there's an error that causes Allocs to always be empty when enabled it
+    %% will be caught by verify_allocations_enabled.
+    ok;
+verify_allocations_output(#{}, {error, not_enabled}) ->
+    ok;
 verify_allocations_output(#{ histogram_start := HistStart,
                              histogram_width := HistWidth },
                     {ok, {HistStart, _UnscannedBytes, ByOrigin}}) ->
@@ -124,8 +133,6 @@ verify_allocations_output(#{ histogram_start := HistStart,
                     [BlockCount, GenTotalBlockCount])
     end,
 
-    ok;
-verify_allocations_output(#{}, {error, not_enabled}) ->
     ok.
 
 %% %% %% %% %% %%
@@ -214,7 +221,8 @@ verify_carriers_output(#{ histogram_start := HistStart,
             ct:fail("Carrier count is ~p, expected at least ~p (SBC).",
                 [CarrierCount, GenSBCCount]);
         CarrierCount >= GenSBCCount ->
-            ok
+            ct:pal("Found ~p blocks, required at least ~p (SBC)." ,
+                [CarrierCount, GenSBCCount])
     end,
 
     ok;
@@ -292,9 +300,19 @@ start_slave(Args) ->
     MicroSecs = erlang:monotonic_time(),
     Name = "instr" ++ integer_to_list(MicroSecs),
     Pa = filename:dirname(code:which(?MODULE)),
-    {ok, Node} = test_server:start_node(list_to_atom(Name),
-                                        slave,
-                                        [{args, "-pa " ++ Pa ++ " " ++ Args}]),
+
+    %% We pass arguments through ZFLAGS as the nightly tests rotate
+    %% +Meamax/+Meamin which breaks the _enabled and _disabled tests unless
+    %% overridden.
+    ZFlags = os:getenv("ERL_ZFLAGS", ""),
+    {ok, Node} = try
+                     os:putenv("ERL_ZFLAGS", ZFlags ++ [" " | Args]),
+                     test_server:start_node(list_to_atom(Name),
+                                            slave,
+                                            [{args, "-pa " ++ Pa}])
+                 after
+                     os:putenv("ERL_ZFLAGS", ZFlags)
+                 end,
     Node.
 
 generate_test_blocks() ->
-- 
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