File 3131-Make-max_transfer_size-parameter-configurable-to-opt.patch of Package erlang

From a40338681382a2f578f101db7f1fcfc5d6490293 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Smyczy=C5=84ski?= <s.smyczynski@simplito.com>
Date: Tue, 1 Jun 2021 13:01:17 +0200
Subject: [PATCH] Make max_transfer_size parameter configurable to optimise
 mnesia table loading time

---
 lib/mnesia/doc/src/mnesia.xml                 |  5 +++++
 lib/mnesia/src/mnesia.erl                     |  2 ++
 lib/mnesia/src/mnesia_loader.erl              | 14 ++++++++++----
 lib/mnesia/src/mnesia_monitor.erl             |  4 ++++
 lib/mnesia/test/mnesia_evil_coverage_test.erl |  1 +
 5 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/lib/mnesia/doc/src/mnesia.xml b/lib/mnesia/doc/src/mnesia.xml
index 9be51a27b3..f39d64b6ab 100644
--- a/lib/mnesia/doc/src/mnesia.xml
+++ b/lib/mnesia/doc/src/mnesia.xml
@@ -3037,6 +3037,11 @@ raise(Name, Amount) ->
           non-zero value, ensure that the remote nodes
           understand this configuration.</p>
       </item>
+      <item>
+        <p><c>-mnesia max_transfer_size Number</c>. Specifies the estimated size
+          in bytes of a single packet of data to be used when copying a table from the local
+          node to another one. Default is <c>64000</c>.</p>
+      </item>
       <item>
         <p><c>-mnesia schema_location Loc</c>. Controls where
           Mnesia looks for its schema. Parameter
diff --git a/lib/mnesia/src/mnesia.erl b/lib/mnesia/src/mnesia.erl
index f9e452cd59..028deccea4 100644
--- a/lib/mnesia/src/mnesia.erl
+++ b/lib/mnesia/src/mnesia.erl
@@ -2553,6 +2553,7 @@ system_info2(core_dir) ->  mnesia_monitor:get_env(core_dir);
 system_info2(no_table_loaders) ->  mnesia_monitor:get_env(no_table_loaders);
 system_info2(dc_dump_limit) ->  mnesia_monitor:get_env(dc_dump_limit);
 system_info2(send_compressed) -> mnesia_monitor:get_env(send_compressed);
+system_info2(max_transfer_size) -> mnesia_monitor:get_env(max_transfer_size);
 
 system_info2(Item) -> exit({badarg, Item}).
 
@@ -2598,6 +2599,7 @@ system_info_items(yes) ->
      no_table_loaders,
      dc_dump_limit,
      send_compressed,
+     max_transfer_size,
      version
     ];
 system_info_items(no) ->
diff --git a/lib/mnesia/src/mnesia_loader.erl b/lib/mnesia/src/mnesia_loader.erl
index a2fde5c808..b7e7f98499 100644
--- a/lib/mnesia/src/mnesia_loader.erl
+++ b/lib/mnesia/src/mnesia_loader.erl
@@ -189,9 +189,6 @@ do_get_disc_copy2(Tab, Reason, Storage = {ext, Alias, Mod}, _Type) ->
 %%                                      Release read lock on table
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
--define(MAX_TRANSFER_SIZE, 7500).
--define(MAX_RAM_FILE_SIZE, 1000000).
--define(MAX_RAM_TRANSFERS, (?MAX_RAM_FILE_SIZE div ?MAX_TRANSFER_SIZE) + 1).
 -define(MAX_NOPACKETS, 20).
 
 net_load_table(Tab, {dumper,{add_table_copy, _}}=Reason, Ns, Cs) ->
@@ -740,6 +737,15 @@ db_put({disc_only_copies, Tab}, Val) ->
 db_put({{ext, Alias, Mod}, Tab}, Val) ->
     ok = Mod:insert(Alias, Tab, Val).
 
+max_transfer_size() ->
+    MaxTransferSize = 64000,
+    case ?catch_val(max_transfer_size) of
+	{'EXIT', _} ->
+	    mnesia_lib:set(max_transfer_size, MaxTransferSize),
+	    MaxTransferSize;
+	Val -> Val
+    end.
+
 %% This code executes at the remote site where the data is
 %% executes in a special copier process.
 
@@ -748,7 +754,7 @@ calc_nokeys(Storage, Tab) ->
     Key = mnesia_lib:db_first(Storage, Tab),
     Recs = mnesia_lib:db_get(Storage, Tab, Key),
     BinSize = size(term_to_binary(Recs)),
-    (?MAX_TRANSFER_SIZE div BinSize) + 1.
+    (max_transfer_size() div BinSize) + 1.
 
 send_table(Pid, Tab, RemoteS, Reason) ->
     case ?catch_val({Tab, storage_type}) of
diff --git a/lib/mnesia/src/mnesia_monitor.erl b/lib/mnesia/src/mnesia_monitor.erl
index 6ea8a0544b..5c1c0395d6 100644
--- a/lib/mnesia/src/mnesia_monitor.erl
+++ b/lib/mnesia/src/mnesia_monitor.erl
@@ -691,6 +691,7 @@ env() ->
      no_table_loaders,
      dc_dump_limit,
      send_compressed,
+     max_transfer_size,
      schema
     ].
 
@@ -741,6 +742,8 @@ default_env(dc_dump_limit) ->
     4;
 default_env(send_compressed) ->
     0;
+default_env(max_transfer_size) ->
+    64000;
 default_env(schema) ->
     [].
 
@@ -790,6 +793,7 @@ do_check_type(pid_sort_order, _) -> false;
 do_check_type(no_table_loaders, N) when is_integer(N), N > 0 -> N;
 do_check_type(dc_dump_limit,N) when is_number(N), N > 0 -> N;
 do_check_type(send_compressed, L) when is_integer(L), L >= 0, L =< 9 -> L;
+do_check_type(max_transfer_size, N) when is_integer(N), N > 0 -> N;
 do_check_type(schema, L) when is_list(L) -> L.
 
 bool(true) -> true;
diff --git a/lib/mnesia/test/mnesia_evil_coverage_test.erl b/lib/mnesia/test/mnesia_evil_coverage_test.erl
index a451c8d0c8..f6f2bfd45e 100644
--- a/lib/mnesia/test/mnesia_evil_coverage_test.erl
+++ b/lib/mnesia/test/mnesia_evil_coverage_test.erl
@@ -140,6 +140,7 @@ system_info(Config) when is_list(Config) ->
     ?match(A when is_atom(A), mnesia:system_info(dump_log_update_in_place)),
     ?match(I when is_integer(I), mnesia:system_info(transaction_log_writes)),
     ?match(I when is_integer(I), mnesia:system_info(send_compressed)),
+    ?match(I when is_integer(I), mnesia:system_info(max_transfer_size)),
     ?match(L when is_list(L), mnesia:system_info(all)),
     ?match(L when is_list(L), mnesia:system_info(backend_types)),
     ?match({'EXIT', {aborted, Reason }} when element(1, Reason) == badarg
-- 
2.26.2