Subject: bug#16039: repeated emacs crashes (in GC?)

From: YAMAMOTO Mitsuharu <[email-masked]>
Date: Wed, 04 Dec 2013 10:48:11 +0900

>>>>> On Wed, 04 Dec 2013 09:43:00 +0900, YAMAMOTO Mitsuharu <[email-masked]> said:

>> Having 136 thousand frames during GC is not unheard of.

> (/ 8720000.0 (* 136 1000))
> 64.11764705882354

> If each frame consumes more than 64 bytes, then it will use up
> 8720000B stack space.

FWIW, the default compiler for Xcode 4.0.2 on Mac OS X 10.6 with the
-O2 option seems to consume 64 bytes for each mark_object frame:

  i686-apple-darwin10-gcc-4.2.1 (GCC) 4.2.1 (Apple Inc. build 5666) (dot 3)

  _mark_object:
  00000000000008a0	pushq	%rbp
  00000000000008a1	movq	%rsp, %rbp
  00000000000008a4	movq	%rbx, 0xffffffffffffffd8(%rbp)
  00000000000008a8	movq	%r12, 0xffffffffffffffe0(%rbp)
  00000000000008ac	movq	%r13, 0xffffffffffffffe8(%rbp)
  00000000000008b0	movq	%r14, 0xfffffffffffffff0(%rbp)
  00000000000008b4	movq	%r15, 0xfffffffffffffff8(%rbp)
  00000000000008b8	subq	$0x40, %rsp

And the one for Xcode 5.0.2 on OS X 10.9 with -O4 does 24 bytes:

  Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn)

  _mark_object:
  0000000000005c70	pushq	%rbp
  0000000000005c71	movq	%rsp, %rbp
  0000000000005c74	pushq	%r15
  0000000000005c76	pushq	%r14
  0000000000005c78	pushq	%r13
  0000000000005c7a	pushq	%r12
  0000000000005c7c	pushq	%rbx
  0000000000005c7d	subq	$0x18, %rsp

				     YAMAMOTO Mitsuharu
				[email-masked]