From 128c7c1876f69812bfe497f2a3f49b5fbce9e0f8 Mon Sep 17 00:00:00 2001
From: Daan <daanl@outlook.com>
Date: Sat, 2 Mar 2024 16:55:13 -0800
Subject: [PATCH] cleanup thp disable a bit

---
 CMakeLists.txt       |  2 +-
 src/prim/unix/prim.c | 31 +++++++++++++++----------------
 2 files changed, 16 insertions(+), 17 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index b5464226..af00e2ee 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -28,7 +28,7 @@ option(MI_DEBUG_UBSAN       "Build with undefined-behavior sanitizer (needs clan
 option(MI_SKIP_COLLECT_ON_EXIT "Skip collecting memory on program exit" OFF)
 option(MI_NO_PADDING        "Force no use of padding even in DEBUG mode etc." OFF)
 option(MI_INSTALL_TOPLEVEL  "Install directly into $CMAKE_INSTALL_PREFIX instead of PREFIX/lib/mimalloc-version" OFF)
-option(MI_NO_THP            "Force disable transparent huge pages support on Linux/Android process wise only" OFF)
+option(MI_NO_THP            "Disable transparent huge pages support on Linux/Android for the mimalloc process only" OFF)
 
 # deprecated options
 option(MI_CHECK_FULL        "Use full internal invariant checking in DEBUG mode (deprecated, use MI_DEBUG_FULL instead)" OFF)
diff --git a/src/prim/unix/prim.c b/src/prim/unix/prim.c
index 33b83322..2035e1a4 100644
--- a/src/prim/unix/prim.c
+++ b/src/prim/unix/prim.c
@@ -31,7 +31,9 @@ terms of the MIT license. A copy of the license can be found in the file
   
 #if defined(__linux__)
   #include <features.h>
+  #if defined(MI_NO_THP)
   #include <sys/prctl.h>
+  #endif
   #if defined(__GLIBC__)
   #include <linux/mman.h> // linux mmap flags
   #else
@@ -129,21 +131,8 @@ static bool unix_detect_overcommit(void) {
   return os_overcommit;
 }
 
-void unix_set_thp(void) {
-#if defined(__linux__) || defined(__ANDROID__)
-#if MI_NO_THP
-  int val;
-  if (prctl(PR_GET_THP_DISABLE, &val, 0, 0, 0) != 0) {
-    // Most likely since distros often come with always/madvise settings.
-    val = 1;
-    // Disabling only for mimalloc process rather than touching system wide settings
-    (void)prctl(PR_SET_THP_DISABLE, &val, 0, 0, 0);
-  }
-#endif
-#endif
-}
-
-void _mi_prim_mem_init( mi_os_mem_config_t* config ) {
+void _mi_prim_mem_init( mi_os_mem_config_t* config ) 
+{
   long psize = sysconf(_SC_PAGESIZE);
   if (psize > 0) {
     config->page_size = (size_t)psize;
@@ -153,7 +142,17 @@ void _mi_prim_mem_init( mi_os_mem_config_t* config ) {
   config->has_overcommit = unix_detect_overcommit();
   config->must_free_whole = false;    // mmap can free in parts
   config->has_virtual_reserve = true; // todo: check if this true for NetBSD?  (for anonymous mmap with PROT_NONE)
-  unix_set_thp();
+
+  // disable transparent huge pages for this process?
+  #if defined(MI_NO_THP) && (defined(__linux__) || defined(__ANDROID__))
+  int val = 0;
+  if (prctl(PR_GET_THP_DISABLE, &val, 0, 0, 0) != 0) {
+    // Most likely since distros often come with always/madvise settings.
+    val = 1;
+    // Disabling only for mimalloc process rather than touching system wide settings
+    (void)prctl(PR_SET_THP_DISABLE, &val, 0, 0, 0);
+  }
+  #endif
 }