diff --git a/bin/minject.exe b/bin/minject.exe
index e5f87800..625816f1 100644
Binary files a/bin/minject.exe and b/bin/minject.exe differ
diff --git a/bin/minject32.exe b/bin/minject32.exe
index d0181028..6857ad0c 100644
Binary files a/bin/minject32.exe and b/bin/minject32.exe differ
diff --git a/src/options.c b/src/options.c
index d2e61218..537b2e6f 100644
--- a/src/options.c
+++ b/src/options.c
@@ -19,8 +19,8 @@ terms of the MIT license. A copy of the license can be found in the file
 #endif
 
 
-static size_t mi_max_error_count   = 16; // stop outputting errors after this
-static size_t mi_max_warning_count = 16; // stop outputting warnings after this
+static long mi_max_error_count   = 16; // stop outputting errors after this (use < 0 for no limit)
+static long mi_max_warning_count = 16; // stop outputting warnings after this (use < 0 for no limit)
 
 static void mi_add_stderr_output(void);
 
@@ -322,11 +322,22 @@ void _mi_fprintf( mi_output_fun* out, void* arg, const char* fmt, ... ) {
   va_end(args);
 }
 
+static void mi_vfprintf_thread(mi_output_fun* out, void* arg, const char* prefix, const char* fmt, va_list args) {
+  if (prefix != NULL && strlen(prefix) <= 32 && !_mi_is_main_thread()) {
+    char tprefix[64];
+    snprintf(tprefix, sizeof(tprefix), "%sthread 0x%zx: ", prefix, _mi_thread_id());
+    mi_vfprintf(out, arg, tprefix, fmt, args);
+  }
+  else {
+    mi_vfprintf(out, arg, prefix, fmt, args);
+  }
+}
+
 void _mi_trace_message(const char* fmt, ...) {
   if (mi_option_get(mi_option_verbose) <= 1) return;  // only with verbose level 2 or higher
   va_list args;
   va_start(args, fmt);
-  mi_vfprintf(NULL, NULL, "mimalloc: ", fmt, args);
+  mi_vfprintf_thread(NULL, NULL, "mimalloc: ", fmt, args);
   va_end(args);
 }
 
@@ -339,17 +350,21 @@ void _mi_verbose_message(const char* fmt, ...) {
 }
 
 static void mi_show_error_message(const char* fmt, va_list args) {
-  if (!mi_option_is_enabled(mi_option_show_errors) && !mi_option_is_enabled(mi_option_verbose)) return;
-  if (mi_atomic_increment_acq_rel(&error_count) > mi_max_error_count) return;
-  mi_vfprintf(NULL, NULL, "mimalloc: error: ", fmt, args);
+  if (!mi_option_is_enabled(mi_option_verbose)) {
+    if (!mi_option_is_enabled(mi_option_show_errors)) return;
+    if (mi_max_error_count >= 0 && (long)mi_atomic_increment_acq_rel(&error_count) > mi_max_error_count) return;
+  }
+  mi_vfprintf_thread(NULL, NULL, "mimalloc: error: ", fmt, args);
 }
 
 void _mi_warning_message(const char* fmt, ...) {
-  if (!mi_option_is_enabled(mi_option_show_errors) && !mi_option_is_enabled(mi_option_verbose)) return;
-  if (mi_atomic_increment_acq_rel(&warning_count) > mi_max_warning_count) return;
+  if (!mi_option_is_enabled(mi_option_verbose)) {
+    if (!mi_option_is_enabled(mi_option_show_errors)) return;
+    if (mi_max_warning_count >= 0 && (long)mi_atomic_increment_acq_rel(&warning_count) > mi_max_warning_count) return;
+  }
   va_list args;
   va_start(args,fmt);
-  mi_vfprintf(NULL, NULL, "mimalloc: warning: ", fmt, args);
+  mi_vfprintf_thread(NULL, NULL, "mimalloc: warning: ", fmt, args);
   va_end(args);
 }
 
diff --git a/src/os.c b/src/os.c
index e5c5bfc4..f0a26c68 100644
--- a/src/os.c
+++ b/src/os.c
@@ -67,7 +67,8 @@ terms of the MIT license. A copy of the license can be found in the file
   On windows initializes support for aligned allocation and
   large OS pages (if MIMALLOC_LARGE_OS_PAGES is true).
 ----------------------------------------------------------- */
-bool    _mi_os_decommit(void* addr, size_t size, mi_stats_t* stats);
+bool _mi_os_decommit(void* addr, size_t size, mi_stats_t* stats);
+bool _mi_os_commit(void* addr, size_t size, bool* is_zero, mi_stats_t* tld_stats);
 
 static void* mi_align_up_ptr(void* p, size_t alignment) {
   return (void*)_mi_align_up((uintptr_t)p, alignment);
@@ -283,21 +284,35 @@ static bool mi_os_mem_free(void* addr, size_t size, bool was_committed, mi_stats
   if (addr == NULL || size == 0) return true; // || _mi_os_is_huge_reserved(addr)
   bool err = false;
 #if defined(_WIN32)
+  DWORD errcode = 0;
   err = (VirtualFree(addr, 0, MEM_RELEASE) == 0);
+  if (err) { errcode = GetLastError(); }
+  if (errcode == ERROR_INVALID_ADDRESS) {
+    // In mi_os_mem_alloc_aligned the fallback path may have returned a pointer inside
+    // the memory region returned by VirtualAlloc; in that case we need to free using
+    // the start of the region.
+    MEMORY_BASIC_INFORMATION info = { 0, 0 };
+    VirtualQuery(addr, &info, sizeof(info));
+    if (info.AllocationBase < addr) {
+      errcode = 0;
+      err = (VirtualFree(info.AllocationBase, 0, MEM_RELEASE) == 0);
+      if (err) { errcode = GetLastError(); }
+    }
+  }
+  if (errcode != 0) {
+    _mi_warning_message("unable to release OS memory: error code 0x%x, addr: %p, size: %zu\n", errcode, addr, size);
+  }
 #elif defined(MI_USE_SBRK) || defined(__wasi__)
-  err = 0; // sbrk heap cannot be shrunk
+  err = false; // sbrk heap cannot be shrunk
 #else
   err = (munmap(addr, size) == -1);
-#endif
-  if (was_committed) _mi_stat_decrease(&stats->committed, size);
-  _mi_stat_decrease(&stats->reserved, size);
   if (err) {
-    _mi_warning_message("munmap failed: %s, addr 0x%8li, size %lu\n", strerror(errno), (size_t)addr, size);
-    return false;
-  }
-  else {
-    return true;
+    _mi_warning_message("unable to release OS memory: %s, addr: %p, size: %zu\n", strerror(errno), addr, size);
   }
+#endif
+  if (was_committed) { _mi_stat_decrease(&stats->committed, size); }
+  _mi_stat_decrease(&stats->reserved, size);
+  return !err;  
 }
 
 #if !(defined(__wasi__) || defined(MI_USE_SBRK) || defined(MAP_ALIGNED))
@@ -328,7 +343,7 @@ static void* mi_win_virtual_allocx(void* addr, size_t size, size_t try_alignment
         return NULL;
       }
       */
-      _mi_warning_message("unable to allocate hinted aligned OS memory (%zu bytes, error code: %x, address: %p, alignment: %d, flags: %x)\n", size, GetLastError(), hint, try_alignment, flags);
+      _mi_warning_message("unable to allocate hinted aligned OS memory (%zu bytes, error code: 0x%x, address: %p, alignment: %d, flags: 0x%x)\n", size, GetLastError(), hint, try_alignment, flags);
     }
   } 
 #endif
@@ -342,7 +357,7 @@ static void* mi_win_virtual_allocx(void* addr, size_t size, size_t try_alignment
     param.Pointer = &reqs;
     void* p = (*pVirtualAlloc2)(GetCurrentProcess(), addr, size, flags, PAGE_READWRITE, &param, 1);
     if (p != NULL) return p;
-    _mi_warning_message("unable to allocate aligned OS memory (%zu bytes, error code: %x, address: %p, alignment: %d, flags: %x)\n", size, GetLastError(), addr, try_alignment, flags);
+    _mi_warning_message("unable to allocate aligned OS memory (%zu bytes, error code: 0x%x, address: %p, alignment: %d, flags: 0x%x)\n", size, GetLastError(), addr, try_alignment, flags);
     // fall through on error
   }
 #endif
@@ -354,6 +369,7 @@ static void* mi_win_virtual_alloc(void* addr, size_t size, size_t try_alignment,
   mi_assert_internal(!(large_only && !allow_large));
   static _Atomic(size_t) large_page_try_ok; // = 0;
   void* p = NULL;
+  // Try to allocate large OS pages (2MiB) if allowed or required.
   if ((large_only || use_large_os_page(size, try_alignment))
       && allow_large && (flags&MEM_COMMIT)!=0 && (flags&MEM_RESERVE)!=0) {
     size_t try_ok = mi_atomic_load_acquire(&large_page_try_ok);
@@ -373,12 +389,13 @@ static void* mi_win_virtual_alloc(void* addr, size_t size, size_t try_alignment,
       }
     }
   }
+  // Fall back to regular page allocation
   if (p == NULL) {
     *is_large = ((flags&MEM_LARGE_PAGES) != 0);
     p = mi_win_virtual_allocx(addr, size, try_alignment, flags);
   }
   if (p == NULL) {
-    _mi_warning_message("unable to allocate OS memory (%zu bytes, error code: %i, address: %p, large only: %d, allow large: %d)\n", size, GetLastError(), addr, large_only, allow_large);
+    _mi_warning_message("unable to allocate OS memory (%zu bytes, error code: 0x%x, address: %p, alignment: %d, flags: 0x%x, large only: %d, allow large: %d)\n", size, GetLastError(), addr, try_alignment, flags, large_only, allow_large);
   }
   return p;
 }
@@ -692,7 +709,7 @@ static void* mi_os_mem_alloc(size_t size, size_t try_alignment, bool commit, boo
 
   #if defined(_WIN32)
     int flags = MEM_RESERVE;
-    if (commit) flags |= MEM_COMMIT;
+    if (commit) { flags |= MEM_COMMIT; }
     p = mi_win_virtual_alloc(NULL, size, try_alignment, flags, false, allow_large, is_large);
   #elif defined(MI_USE_SBRK) || defined(__wasi__)
     MI_UNUSED(allow_large);
@@ -723,45 +740,27 @@ static void* mi_os_mem_alloc_aligned(size_t size, size_t alignment, bool commit,
   // try first with a hint (this will be aligned directly on Win 10+ or BSD)
   void* p = mi_os_mem_alloc(size, alignment, commit, allow_large, is_large, stats);
   if (p == NULL) return NULL;
-
+  
   // if not aligned, free it, overallocate, and unmap around it
   if (((uintptr_t)p % alignment != 0)) {
     mi_os_mem_free(p, size, commit, stats);
+    _mi_warning_message("unable to allocate aligned OS memory directly, fall back to over-allocation (%zu bytes, address: %p, commit: %d, is_large: %d)\n", size, p, commit, *is_large);
     if (size >= (SIZE_MAX - alignment)) return NULL; // overflow
-    size_t over_size = size + alignment;
+    const size_t over_size = size + alignment;
 
 #if _WIN32
-    // over-allocate and than re-allocate exactly at an aligned address in there.
-    // this may fail due to threads allocating at the same time so we
-    // retry this at most 3 times before giving up.
-    // (we can not decommit around the overallocation on Windows, because we can only
-    //  free the original pointer, not one pointing inside the area)
-    int flags = MEM_RESERVE;
-    if (commit) flags |= MEM_COMMIT;
-    for (int tries = 0; tries < 3; tries++) {
-      // over-allocate to determine a virtual memory range
-      p = mi_os_mem_alloc(over_size, alignment, commit, false, is_large, stats);
-      if (p == NULL) return NULL; // error
-      if (((uintptr_t)p % alignment) == 0) {
-        // if p happens to be aligned, just decommit the left-over area
-        _mi_os_decommit((uint8_t*)p + size, over_size - size, stats);
-        break;
-      }
-      else {
-        // otherwise free and allocate at an aligned address in there
-        mi_os_mem_free(p, over_size, commit, stats);
-        void* aligned_p = mi_align_up_ptr(p, alignment);
-        p = mi_win_virtual_alloc(aligned_p, size, alignment, flags, false, allow_large, is_large);
-        if (p != NULL) {
-          _mi_stat_increase(&stats->reserved, size);
-          if (commit) { _mi_stat_increase(&stats->committed, size); }
-        }
-        if (p == aligned_p) break; // success!
-        if (p != NULL) { // should not happen?
-          mi_os_mem_free(p, size, commit, stats);
-          p = NULL;
-        }
-      }
+    // over-allocate uncommitted (virtual) memory
+    p = mi_os_mem_alloc(over_size, 0 /*alignment*/, false /* commit? */, false /* allow_large */, is_large, stats);
+    if (p == NULL) return NULL;
+    
+    // set p to the aligned part in the full region
+    // note: this is dangerous on Windows as VirtualFree needs the actual region pointer
+    // but in mi_os_mem_free we handle this (hopefully exceptional) situation.
+    p = mi_align_up_ptr(p, alignment);
+
+    // explicitly commit only the aligned part
+    if (commit) {
+      _mi_os_commit(p, size, NULL, stats);
     }
 #else
     // overallocate...