Suppress info strings before 'uci'

On Windows, Stockfish wouldn't launch in some GUI because we output some
info strings (about the use of large pages) before sending the 'uci'
command. It seems more robust to suppress these info strings, and instead
to add a proper section section in the Readme about large pages use.

fixes https://github.com/official-stockfish/Stockfish/issues/3052
closes https://github.com/official-stockfish/Stockfish/pull/3147

No functional change

diff --git a/README.md b/README.md
index 255ebce2afc02ec6b3190e6c2bd9ae578b4b559d..409d0a1036c56bf1dfbdd025fc871fef15d544d8 100644 (file)
--- a/README.md
+++ b/README.md
@@ -198,8 +198,8 @@ the 50-move rule.
 
 Stockfish supports large pages on Linux and Windows. Large pages make
 the hash access more efficient, improving the engine speed, especially
 
 Stockfish supports large pages on Linux and Windows. Large pages make
 the hash access more efficient, improving the engine speed, especially

-on large hash sizes. Typical increases are 5..10% in terms of nps, but
-speed increases up to 30% have been measured. The support is
+on large hash sizes. Typical increases are 5..10% in terms of nodes per
+second, but speed increases up to 30% have been measured. The support is

 automatic. Stockfish attempts to use large pages when available and
 will fall back to regular memory allocation when this is not the case.
 
 automatic. Stockfish attempts to use large pages when available and
 will fall back to regular memory allocation when this is not the case.
 


@@ -213,11 +213,11 @@ are already enabled and no configuration is needed.
 
 The use of large pages requires "Lock Pages in Memory" privilege. See
 [Enable the Lock Pages in Memory Option (Windows)](https://docs.microsoft.com/en-us/sql/database-engine/configure-windows/enable-the-lock-pages-in-memory-option-windows)
 
 The use of large pages requires "Lock Pages in Memory" privilege. See
 [Enable the Lock Pages in Memory Option (Windows)](https://docs.microsoft.com/en-us/sql/database-engine/configure-windows/enable-the-lock-pages-in-memory-option-windows)

-on how to enable this privilege. Logout/login may be needed
-afterwards. Due to memory fragmentation, it may not always be
-possible to allocate large pages even when enabled. A reboot
-might alleviate this problem. To determine whether large pages
-are in use, see the engine log.
+on how to enable this privilege, then run [RAMMap](https://docs.microsoft.com/en-us/sysinternals/downloads/rammap)
+to double-check that large pages are used. We suggest that you reboot
+your computer after you have enabled large pages, because long Windows
+sessions suffer from memory fragmentation which may prevent Stockfish
+from getting large pages: a fresh session is better in this regard.

 
 ## Compiling Stockfish yourself from the sources
 
 
 ## Compiling Stockfish yourself from the sources
 


@@ -232,8 +232,8 @@ targets with corresponding descriptions.
 ```
     cd src
     make help
 ```
     cd src
     make help

-    make build ARCH=x86-64-modern

     make net
     make net

+    make build ARCH=x86-64-modern

 ```
 
 When not using the Makefile to compile (for instance with Microsoft MSVC) you
 ```
 
 When not using the Makefile to compile (for instance with Microsoft MSVC) you

diff --git a/src/misc.cpp b/src/misc.cpp
index d9bc47e3c886f964e58202599c27a3d2182507be..a16a6e90a3daddefe82a7716934d86baf2cac31b 100644 (file)
--- a/src/misc.cpp
+++ b/src/misc.cpp
@@ -408,22 +408,8 @@ static void* aligned_large_pages_alloc_win(size_t allocSize) {
 
 void* aligned_large_pages_alloc(size_t allocSize) {
 
 
 void* aligned_large_pages_alloc(size_t allocSize) {
 

-  static bool firstCall = true;
-  void* mem;
-

   // Try to allocate large pages
   // Try to allocate large pages

-  mem = aligned_large_pages_alloc_win(allocSize);
-
-  // Suppress info strings on the first call. The first call occurs before 'uci'
-  // is received and in that case this output confuses some GUIs.
-  if (!firstCall)
-  {
-      if (mem)
-          sync_cout << "info string Hash table allocation: Windows large pages used." << sync_endl;
-      else
-          sync_cout << "info string Hash table allocation: Windows large pages not used." << sync_endl;
-  }
-  firstCall = false;
+  void* mem = aligned_large_pages_alloc_win(allocSize);

 
   // Fall back to regular, page aligned, allocation if necessary
   if (!mem)
 
   // Fall back to regular, page aligned, allocation if necessary
   if (!mem)