Add cmake variable to set the max app thread stack size (#346)

build-scripts/config_common.cmake

@@ -162,4 +162,7 @@ if (WAMR_DISABLE_HW_BOUND_CHECK EQUAL 1)
   add_definitions (-DWASM_DISABLE_HW_BOUND_CHECK=1)
   message ("     Hardware boundary check disabled")
 endif ()
+if (DEFINED WAMR_APP_THREAD_STACK_SIZE_MAX)
+  add_definitions (-DAPP_THREAD_STACK_SIZE_MAX=${WAMR_APP_THREAD_STACK_SIZE_MAX})
+endif ()
 

core/config.h

@@ -216,11 +216,12 @@ enum {
 #if !defined(BH_PLATFORM_ZEPHYR) && !defined(BH_PLATFORM_ALIOS_THINGS)
 #define APP_THREAD_STACK_SIZE_DEFAULT (32 * 1024)
 #define APP_THREAD_STACK_SIZE_MIN (24 * 1024)
-#define APP_THREAD_STACK_SIZE_MAX (256 * 1024)
 #else
 #define APP_THREAD_STACK_SIZE_DEFAULT (6 * 1024)
 #define APP_THREAD_STACK_SIZE_MIN (4 * 1024)
-#define APP_THREAD_STACK_SIZE_MAX (256 * 1024)
+#endif
+#if !defined(APP_THREAD_STACK_SIZE_MAX)
+#define APP_THREAD_STACK_SIZE_MAX (8 * 1024 * 1024)
 #endif
 
 /* Reserved bytes to the native thread stack boundary, throw native

core/shared/platform/common/posix/posix_thread.c

@@ -242,12 +242,19 @@ uint8 *os_thread_get_stack_boundary()
     uint8 *addr = NULL;
     size_t stack_size, guard_size;
     int page_size = getpagesize();
+    size_t max_stack_size = (APP_THREAD_STACK_SIZE_MAX + page_size - 1)
+                            & ~(page_size - 1);
+
+    if (max_stack_size < APP_THREAD_STACK_SIZE_DEFAULT)
+        max_stack_size = APP_THREAD_STACK_SIZE_DEFAULT;
 
 #ifdef __linux__
     if (pthread_getattr_np(self, &attr) == 0) {
         pthread_attr_getstack(&attr, (void**)&addr, &stack_size);
         pthread_attr_getguardsize(&attr, &guard_size);
         pthread_attr_destroy(&attr);
+        if (stack_size > max_stack_size)
+            addr = addr + stack_size - max_stack_size;
         if (guard_size < (size_t)page_size)
             /* Reserved 1 guard page at least for safety */
             guard_size = (size_t)page_size;
@@ -257,7 +264,10 @@ uint8 *os_thread_get_stack_boundary()
 #elif defined(__APPLE__)
     if ((addr = (uint8*)pthread_get_stackaddr_np(self))) {
         stack_size = pthread_get_stacksize_np(self);
-        addr -= stack_size;
+        if (stack_size > max_stack_size)
+            addr -= max_stack_size;
+        else
+            addr -= stack_size;
         /* Reserved 1 guard page at least for safety */
         addr += page_size;
     }

doc/build_wamr.md

@@ -68,6 +68,10 @@ cmake -DWAMR_BUILD_PLATFORM=linux -DWAMR_BUILD_TARGET=ARM
 - **WAMR_DISABLE_HW_BOUND_CHECK**=1/0, default to enable if not set and supported by platform
 > Note: by default only platform linux/darwin/android/vxworks 64-bit will enable boundary check with hardware trap in AOT or JIT mode, and the wamrc tool will generate AOT code without boundary check instructions in all 64-bit targets except SGX to improve performance.
 
+#### **Set maximum app thread stack size**
+- **WAMR_APP_THREAD_STACK_SIZE_MAX**=n, default to 8 MB (8388608) if not set
+> Note: the AOT boundary check with hardware trap mechanism might consume large stack since the OS may lazily grow the stack mapping as a guard page is hit, we may use this configuration to reduce the total stack usage, e.g. -DWAMR_APP_THREAD_STACK_SIZE_MAX=131072 (128 KB).
+
 **Combination of configurations:**
 
 We can combine the configurations. For example, if we want to disable interpreter, enable AOT and WASI, we can run command: