From bcce4d52bf1494746f4dd7f5569e542cbfdf5d36 Mon Sep 17 00:00:00 2001
From: Daan Leijen <daan@microsoft.com>
Date: Mon, 18 Oct 2021 20:39:39 -0700
Subject: [PATCH 1/3] fix bug in determination of block size in pre-reserved
 arena memory

---
 src/arena.c | 2 +-
 src/init.c  | 4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/arena.c b/src/arena.c
index 0e6615a4..a4e473a3 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -287,7 +287,7 @@ bool mi_manage_os_memory(void* start, size_t size, bool is_committed, bool is_la
     is_committed = true;
   }
   
-  const size_t bcount = mi_block_count_of_size(size);
+  const size_t bcount = size / MI_ARENA_BLOCK_SIZE; 
   const size_t fields = _mi_divide_up(bcount, MI_BITMAP_FIELD_BITS);
   const size_t bitmaps = (is_committed ? 2 : 3);
   const size_t asize  = sizeof(mi_arena_t) + (bitmaps*fields*sizeof(mi_bitmap_field_t));
diff --git a/src/init.c b/src/init.c
index c0f09b5e..d899f6ad 100644
--- a/src/init.c
+++ b/src/init.c
@@ -498,7 +498,9 @@ void mi_process_init(void) mi_attr_noexcept {
   } 
   if (mi_option_is_enabled(mi_option_reserve_os_memory)) {
     long ksize = mi_option_get(mi_option_reserve_os_memory);
-    if (ksize > 0) mi_reserve_os_memory((size_t)ksize*KiB, true, true);
+    if (ksize > 0) {
+      mi_reserve_os_memory(_mi_divide_up((size_t)ksize*KiB, MI_SEGMENT_SIZE), true, true);
+    }
   }
 }
 

From 22c2fd82cc6e339ecdf34bf28accf1f6658f5509 Mon Sep 17 00:00:00 2001
From: Daan Leijen <daan@microsoft.com>
Date: Mon, 18 Oct 2021 20:44:19 -0700
Subject: [PATCH 2/3] ensure managed os memory is at least one arena block in
 size

---
 src/arena.c | 4 +++-
 src/init.c  | 2 +-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/arena.c b/src/arena.c
index a4e473a3..b786ffb4 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -282,6 +282,8 @@ static bool mi_arena_add(mi_arena_t* arena) {
 
 bool mi_manage_os_memory(void* start, size_t size, bool is_committed, bool is_large, bool is_zero, int numa_node) mi_attr_noexcept
 {
+  if (size < MI_ARENA_BLOCK_SIZE) return false;
+
   if (is_large) {
     mi_assert_internal(is_committed);
     is_committed = true;
@@ -321,7 +323,7 @@ bool mi_manage_os_memory(void* start, size_t size, bool is_committed, bool is_la
 // Reserve a range of regular OS memory
 int mi_reserve_os_memory(size_t size, bool commit, bool allow_large) mi_attr_noexcept 
 {
-  size = _mi_os_good_alloc_size(size);
+  size = _mi_align_up(size, MI_ARENA_BLOCK_SIZE); // at least one block
   bool large = allow_large;
   void* start = _mi_os_alloc_aligned(size, MI_SEGMENT_ALIGN, commit, &large, &_mi_stats_main);
   if (start==NULL) return ENOMEM;
diff --git a/src/init.c b/src/init.c
index d899f6ad..c088cada 100644
--- a/src/init.c
+++ b/src/init.c
@@ -499,7 +499,7 @@ void mi_process_init(void) mi_attr_noexcept {
   if (mi_option_is_enabled(mi_option_reserve_os_memory)) {
     long ksize = mi_option_get(mi_option_reserve_os_memory);
     if (ksize > 0) {
-      mi_reserve_os_memory(_mi_divide_up((size_t)ksize*KiB, MI_SEGMENT_SIZE), true, true);
+      mi_reserve_os_memory((size_t)ksize*KiB, true, true);
     }
   }
 }

From 10c31f9b41f5559e459dc30cf463cc750bfa67ac Mon Sep 17 00:00:00 2001
From: Daan Leijen <daan@microsoft.com>
Date: Tue, 19 Oct 2021 15:13:01 -0700
Subject: [PATCH 3/3] fix warnings

---
 src/stats.c     | 4 ++--
 test/test-api.c | 1 +
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/stats.c b/src/stats.c
index dda55cda..115d938e 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -153,8 +153,8 @@ static void mi_printf_amount(int64_t n, int64_t unit, mi_output_fun* out, void*
     const int64_t tens = (n / (divider/10));
     const long whole = (long)(tens/10);
     const long frac1 = (long)(tens%10);
-    char unitdesc[16];
-    snprintf(unitdesc, 16, "%s%s%s", magnitude, (base==1024 ? "i" : ""), suffix);
+    char unitdesc[8];
+    snprintf(unitdesc, 8, "%s%s%s", magnitude, (base==1024 ? "i" : ""), suffix);
     snprintf(buf, len, "%ld.%ld %-3s", whole, (frac1 < 0 ? -frac1 : frac1), unitdesc);
   }
   _mi_fprintf(out, arg, (fmt==NULL ? "%11s" : fmt), buf);
diff --git a/test/test-api.c b/test/test-api.c
index 55c80431..f72cfaf5 100644
--- a/test/test-api.c
+++ b/test/test-api.c
@@ -4,6 +4,7 @@ This is free software; you can redistribute it and/or modify it under the
 terms of the MIT license. A copy of the license can be found in the file
 "LICENSE" at the root of this distribution.
 -----------------------------------------------------------------------------*/
+#pragma GCC diagnostic ignored "-Walloc-size-larger-than="
 
 /*
 Testing allocators is difficult as bugs may only surface after particular