Bug #5901: OpenBSD "[FATAL] failed to allocate memory"

• Status: Closed
• Assignee: authorNari (Narihiro Nakamura)
• Target version: -
• ruby -v: ruby 2.0.0dev (2012-01-16 trunk 34316) [x86_64-openbsd5.0]

[kernigh (George Koehler)]

=begin
Ruby trunk fails to build with OpenBSD. During the build, miniruby fails with message
[FATAL] failed to allocate memory

OpenBSD has a broken posix_memalign(). Ruby fails in gc.c, because posix_memalign() fails and aligned_malloc() returns NULL. OpenBSD's manual for posix_memalign ((URL:http://xrl.us/bmow7c)) says:

BUGS
Only alignments up to the page size can be specified.

Ruby wants alignment of 16 kilobytes, but my page size is only 4 kilobytes.

I tried to edit gc.c. My first attempt (bad-fix-never-apply.diff) was good enough to build Ruby, but it did not always work, and some tests failed. So I reverted gc.c and tried again.

My second attempt (smaller-heap-for-openbsd.diff) was much simpler. I changed the values of HEAP_ALIGN*, shrinking the heap size from 16 kilobytes to 4 kilobytes, which is not larger than my page size. More tests pass. The only failures in 'make test' are in bootstraptest/test_thread.rb. Those tests seem to create an infinite loop in Ruby, and I needed to kill -9 those processes. Some tests in 'make test-all' failed the same way, with the infinite loop.
=end

[kosaki (Motohiro KOSAKI)]

You don't have to edit gc.c. Instead, please make a workaround in configure.in. We only need aligned alloc, and don't exactly need posix_memalign.

[naruse (Yui NARUSE)]

• Status changed from Open to Assigned
• Assignee set to authorNari (Narihiro Nakamura)

[kernigh (George Koehler)]

Motohiro KOSAKI wrote:

You don't have to edit gc.c. Instead, please make a workaround in configure.in. We only need aligned alloc, and don't exactly need posix_memalign.

Even if configure.in would check that posix_memalign is broken, there seems to be no other way to do aligned alloc for OpenBSD. One would need to edit gc.c to do something different for OpenBSD.

[authorNari (Narihiro Nakamura)]

Hi.

I make the following patch. Is it acceptable?

diff --git a/configure.in b/configure.in
index 085dfcf..f41ef3b 100644
--- a/configure.in
+++ b/configure.in
@@ -1292,6 +1292,13 @@ main() {
CFLAGS="$save_CFLAGS"])
AC_DEFINE_UNQUOTED(GC_MARK_STACKFRAME_WORD, $rb_cv_gc_mark_stackframe_word)

+AS_CASE(["$target_os"],
+[openbsd*], [

• AC_DEFINE_UNQUOTED(HEAP_ALIGN_LOG, 12)
• AC_DEFINE_UNQUOTED(HEAP_ALIGN, 0x1000)
• AC_DEFINE_UNQUOTED(HEAP_ALIGN_MASK, 0x0fff)
• ])

dnl Checks for library functions.
AC_TYPE_GETGROUPS
diff --git a/gc.c b/gc.c
index 4c906e7..b90cf35 100644
--- a/gc.c
+++ b/gc.c
@@ -536,10 +536,13 @@ rb_objspace_free(rb_objspace_t *objspace)
}
#endif

-/* tiny heap size: 16KB /
+#ifndef HEAP_ALIGN_LOG
+/ default tiny heap size: 16KB */
#define HEAP_ALIGN_LOG 14
#define HEAP_ALIGN 0x4000
#define HEAP_ALIGN_MASK 0x3fff
+#endif
+
#define REQUIRED_SIZE_BY_MALLOC (sizeof(size_t) * 5)
#define HEAP_SIZE (HEAP_ALIGN - REQUIRED_SIZE_BY_MALLOC)

[kernigh (George Koehler)]

• File smaller-heap-3.diff smaller-heap-3.diff added

I reverted my own changes. Then I tried to apply patch by Narihiro Nakamura, but I got patch conflict with svn r34399. After I solved conflict, I can compile and run Ruby, 'make test' passes all tests, and 'make test-all' has 0 failures and 0 errors. My system is OpenBSD 5.0/amd64.

After I solved conflict, patch looks like this:

Index: configure.in

--- configure.in (revision 34399)
+++ configure.in (working copy)
@@ -1292,7 +1292,12 @@
CFLAGS="$save_CFLAGS"])
AC_DEFINE_UNQUOTED(GC_MARK_STACKFRAME_WORD, $rb_cv_gc_mark_stackframe_word)

+AS_CASE(["$target_os"],
+[openbsd*], [

• AC_DEFINE_UNQUOTED(HEAP_ALIGN_LOG, 12)

• ])

dnl Checks for library functions.
AC_TYPE_GETGROUPS
AC_TYPE_SIGNAL
Index: gc.c

--- gc.c (revision 34399)
+++ gc.c (working copy)
@@ -536,8 +536,11 @@
}
#endif

-/* tiny heap size: 16KB /
+#ifndef HEAP_ALIGN_LOG
+/ default tiny heap size: 16KB */
#define HEAP_ALIGN_LOG 14
+#endif
+
#define HEAP_ALIGN (1UL << HEAP_ALIGN_LOG)
#define HEAP_ALIGN_MASK (~(~0UL << HEAP_ALIGN_LOG))
#define REQUIRED_SIZE_BY_MALLOC (sizeof(size_t) * 5)

[authorNari (Narihiro Nakamura)]

• Status changed from Assigned to Closed
• % Done changed from 0 to 100

This issue was solved with changeset r34404.
George, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

• configure.in (HEAP_ALIGN_LOG): HEAP_ALIGN_LOG should be page
  size in OpenBSD. [ruby-core:42158][Bug #5901]

• gc.c : avoid to redefine.