Revert "Merge pull request #10736 from xavierleroy/bigger-stack"

This reverts commit 6c2fb7b, reversing
changes made to b6aa64e.

Changes

@@ -67,9 +67,6 @@ OCaml 4.14.0
 - #10730, 10731: Fix bug in `Obj.reachable_words` causing a slowdown when called
   multiple time (Alain Frisch, report by ygrek, review by Xavier Leroy)
 
-- #10736: Try to increase the maximal stack size for native-code applications
-  (Xavier Leroy, review by Damien Doligez)
-
 ### Code generation and optimizations:
 
 - #10578: Increase the number of integer registers used for

configure.ac

@@ -731,13 +731,13 @@ AS_CASE([$host],
     flexlink_flags="-chain $flexdll_chain -stack 16777216"],
   [x86_64-w64-mingw32],
     [flexdll_chain='mingw64'
-    flexlink_flags="-chain $flexdll_chain -stack 67108864"],
+    flexlink_flags="-chain $flexdll_chain -stack 33554432"],
   [i686-pc-windows],
     [flexdll_chain='msvc'
     flexlink_flags="-merge-manifest -stack 16777216"],
   [x86_64-pc-windows],
     [flexdll_chain='msvc64'
-    flexlink_flags="-x64 -merge-manifest -stack 67108864"])
+    flexlink_flags="-x64 -merge-manifest -stack 33554432"])
 
 AS_IF([test x"$supports_shared_libraries" != 'xfalse'], [
   AC_MSG_CHECKING([for flexdll sources])

manual/src/cmds/native.etex

@@ -206,48 +206,13 @@ the following environment variables are also consulted:
 \begin{options}
 \item["OCAMLRUNPARAM"]  Same usage as in "ocamlrun"
   (see section~\ref{s:ocamlrun-options}), except that option "l"
-  is ignored.  (How to control the stack size is explained in
-  section~\ref{s:native:stacksize}.)
+  is ignored (the operating system's stack size limit
+  is used instead).
 \item["CAMLRUNPARAM"]  If "OCAMLRUNPARAM" is not found in the
   environment, then "CAMLRUNPARAM" will be used instead.  If
   "CAMLRUNPARAM" is not found, then the default values will be used.
 \end{options}
 
-\section{s:native:stacksize}{Size of the stack}
-
-Native-code executables produced by the "ocamlopt" compiler use the
-stack managed by the operating system to implement function calls in
-non-tail positions.  The system stack grows on demand up to a certain
-size limit maintained by the operating system.  We now explain how this
-size limit is determined and can be controlled.
-
-\begin{unix}
-Linux, macOS, and other Unix-like operating systems maintain two
-limits for the stack size: a current limit and a hard limit.  These
-limits can be modified (as long as the hard limit is not exceeded)
-with the "ulimit -s" shell command or the "setrlimit" system call.
-At start-up, executables generated by "ocamlopt" try to set a
-comfortable limit for the stack size, as follows:
-\begin{itemize}
-\item If the current limit is already at the hard limit, as happens if
-  a "ulimit -s" command was issued in the shell that starts the
-  executable, the stack size limit is unchanged.
-\item If the hard limit is ``unlimited'', as in many Linux
-  distributions, the stack size limit is raised to 1 Gibytes for 64-bit
-  platforms and 16 Mibytes for 32-bit platforms.
-\item Otherwise, the stack size limit is raised to the hard limit.
-  For example, this gives a limit of 64 Mibytes under macOS and 512
-  Mibytes under FreeBSD 64 bits.
-\end{itemize}
-\end{unix}
-
-\begin{windows}
-By default, the maximal size of the system stack is 64 Mibytes for 64-bit
-executables and 16 Mibytes for 32-bit executables.  It cannot be
-changed dynamically.  It can be changed at link-time by passing the
-appropriate "-stack" option to the "flexlink" linker.
-\end{windows}
-
 \section{s:compat-native-bytecode}{Compatibility with the bytecode compiler}
 
 This section lists the known incompatibilities between the bytecode

runtime/caml/osdeps.h

@@ -108,9 +108,6 @@ extern char_os *caml_secure_getenv(char_os const *var);
    cannot be determined, return -1. */
 extern int caml_num_rows_fd(int fd);
 
-/* Try to increase the size of the native stack */
-extern void caml_increase_native_stack_size(void);
-
 #ifdef _WIN32
 
 extern int caml_win32_rename(const wchar_t *, const wchar_t *);

runtime/startup_nat.c

@@ -124,7 +124,6 @@ value caml_startup_common(char_os **argv, int pooling)
   if (!caml_startup_aux(pooling))
     return Val_unit;
 
-  caml_increase_native_stack_size();
   caml_init_frame_descriptors();
   caml_init_locale();
 #if defined(_MSC_VER) && __STDC_SECURE_LIB__ >= 200411L

runtime/unix.c

@@ -29,8 +29,6 @@
 #include <errno.h>
 #include <sys/ioctl.h>
 #include <fcntl.h>
-#include <sys/time.h>
-#include <sys/resource.h>
 #include "caml/config.h"
 #if defined(SUPPORT_DYNAMIC_LINKING) && !defined(BUILDING_LIBCAMLRUNS)
 #define WITH_DYNAMIC_LINKING
@@ -436,29 +434,3 @@ int caml_num_rows_fd(int fd)
   return -1;
 #endif
 }
-
-void caml_increase_native_stack_size(void)
-{
-#ifdef RLIMIT_STACK
-  struct rlimit lim;
-  rlim_t newlim;
-  if (getrlimit(RLIMIT_STACK, &lim) == -1) return;
-  newlim = lim.rlim_max;
-  if (newlim == RLIM_INFINITY) {
-#ifdef ARCH_SIXTYFOUR
-    newlim = 1024*1024*1024; /* 1G */
-#else
-    newlim = 16*1024*1024; /* 16M */
-#endif
-  }
-  if (lim.rlim_cur >= newlim) return;
-  lim.rlim_cur = newlim;
-  if (setrlimit(RLIMIT_STACK, &lim) == -1) {
-    caml_gc_message(0x08, "Failed to increase native stack size\n");
-  } else {
-    caml_gc_message(0x08, "Increased native stack size to "
-                          "%"ARCH_INT64_PRINTF_FORMAT"u\n",
-                    (ARCH_UINT64_TYPE) newlim);
-  }
-#endif
-}

runtime/win32.c

@@ -1087,7 +1087,3 @@ CAMLexport clock_t caml_win32_clock(void)
   clocks_per_sec = INT64_LITERAL(10000000U) / (ULONGLONG)CLOCKS_PER_SEC;
   return (clock_t)(total / clocks_per_sec);
 }
-
-void caml_increase_native_stack_size(void)
-{
-}