From f2d592185f614e139872ccb84309d88325b54445 Mon Sep 17 00:00:00 2001
From: Andy Wingo <wingo@pobox.com>
Date: Wed, 19 Feb 2014 11:11:46 +0100
Subject: [PATCH] Default stack size is one page.

* libguile/vm.c (initialize_default_stack_size): Initial stack size is
  one page.
---
 libguile/vm.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/libguile/vm.c b/libguile/vm.c
index 463dac66e..93a37200b 100644
--- a/libguile/vm.c
+++ b/libguile/vm.c
@@ -713,12 +713,15 @@ scm_i_call_with_current_continuation (SCM proc)
  * VM
  */
 
+/* The page size.  */
+static size_t page_size;
+
 /* Hard stack limit is 512M words: 2 gigabytes on 32-bit machines, 4 on
    64-bit machines.  */
 static const size_t hard_max_stack_size = 512 * 1024 * 1024;
 
-/* Initial stack size: 4 or 8 kB.  */
-static const size_t initial_stack_size = 1024;
+/* Initial stack size.  Defaults to one page.  */
+static size_t initial_stack_size;
 
 /* Default soft stack limit is 1M words (4 or 8 megabytes).  */
 static size_t default_max_stack_size = 1024 * 1024;
@@ -726,9 +729,15 @@ static size_t default_max_stack_size = 1024 * 1024;
 static void
 initialize_default_stack_size (void)
 {
-  int size = scm_getenv_int ("GUILE_STACK_SIZE", (int) default_max_stack_size);
-  if (size >= initial_stack_size && (size_t) size < ((size_t) -1) / sizeof(SCM))
-    default_max_stack_size = size;
+  initial_stack_size = page_size / sizeof (SCM);
+
+  {
+    int size;
+    size = scm_getenv_int ("GUILE_STACK_SIZE", (int) default_max_stack_size);
+    if (size >= initial_stack_size
+        && (size_t) size < ((size_t) -1) / sizeof(SCM))
+      default_max_stack_size = size;
+  }
 }
 
 #define VM_NAME vm_regular_engine
@@ -858,8 +867,6 @@ make_vm (void)
 }
 #undef FUNC_NAME
 
-static size_t page_size;
-
 static void
 return_unused_stack_to_os (struct scm_vm *vp)
 {
-- 
2.20.1