From f6a2add230fd8d30101e29a9ac5d3420a8c3ca57 Mon Sep 17 00:00:00 2001
From: Igor Bonadio and Helton Alponti <elo7-developer@elo7.com>
Date: Mon, 23 Oct 2017 16:58:15 +0000
Subject: [PATCH] Activate flag MAP_POPULATE when compiled with -DMAP_POPULATE

---
 lib/marisa/grimoire/io/mapper.cc | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/marisa/grimoire/io/mapper.cc b/lib/marisa/grimoire/io/mapper.cc
index 6ae0ee3..2c397ba 100644
--- a/lib/marisa/grimoire/io/mapper.cc
+++ b/lib/marisa/grimoire/io/mapper.cc
@@ -145,7 +145,12 @@ void Mapper::open_(const char *filename) {
   fd_ = ::open(filename, O_RDONLY);
   MARISA_THROW_IF(fd_ == -1, MARISA_IO_ERROR);
 
+#ifdef MAP_POPULATE
+  origin_ = ::mmap(NULL, size_, PROT_READ, MAP_SHARED | MAP_POPULATE, fd_, 0);
+#else
   origin_ = ::mmap(NULL, size_, PROT_READ, MAP_SHARED, fd_, 0);
+#endif
+
   MARISA_THROW_IF(origin_ == MAP_FAILED, MARISA_IO_ERROR);
 
   ptr_ = static_cast<const char *>(origin_);