Feature #4568: [PATCH] file.c (rb_group_member): kill 256K of stack usage

• Status: Closed
• Assignee: kosaki (Motohiro KOSAKI)
• Target version: 2.0.0

[normalperson (Eric Wong)]

=begin
It was using 256K stack on my x86_64 machine.

Found with scripts/checkstack.pl in the Linux kernel source:

objdump -D ./ruby | ~/linux-2.6/scripts/checkstack.pl x86_64

Also pushed to my repo: git pull git://bogomips.org/ruby stack-reduce

=end

[normalperson (Eric Wong)]

=begin
Lowering RUBY_STACK_MIN_LIMIT to 64KB across the board in
thread_pthread.c seems to work fine for check, test-rubyspec,
benchmark-each.

No real code, though, and I also don't know what outside C extensions
do, but 64KB is the PTHREAD_STACK_MIN for my platform (and I've always
felt it was too high).

diff --git a/thread_pthread.c b/thread_pthread.c
index ad6f716..a015873 100644
--- a/thread_pthread.c
+++ b/thread_pthread.c
@@ -630,11 +630,7 @@ use_cached_thread(rb_thread_t *th)
}

enum {
-#ifdef SYMBIAN32

• RUBY_STACK_MIN_LIMIT = 64 * 1024, /* 64KB: Let's be slightly more frugal on mobile platform */
  -#else
• RUBY_STACK_MIN_LIMIT = 512 * 1024, /* 512KB */
  -#endif

• RUBY_STACK_MIN_LIMIT = 64 * 1024, /* 64KB */
  RUBY_STACK_SPACE_LIMIT = 1024 * 1024
  };

--
Eric Wong
=end

[kosaki (Motohiro KOSAKI)]

• Status changed from Open to Closed
• Assignee set to kosaki (Motohiro KOSAKI)

=begin
Commited by r31259.
=end

[normalperson (Eric Wong)]

=begin
Lowering RUBY_STACK_MIN_LIMIT to 64KB across the board in
thread_pthread.c seems to work fine for check, test-rubyspec,
benchmark-each.

No real code, though, and I also don't know what outside C extensions
do, but 64KB is the PTHREAD_STACK_MIN for my platform (and I've always
felt it was too high).

diff --git a/thread_pthread.c b/thread_pthread.c
index ad6f716..a015873 100644
--- a/thread_pthread.c
+++ b/thread_pthread.c
@@ -630,11 +630,7 @@ use_cached_thread(rb_thread_t *th)
}

enum {
-#ifdef SYMBIAN32

• RUBY_STACK_MIN_LIMIT = 64 * 1024, /* 64KB: Let's be slightly more frugal on mobile platform */
  -#else
• RUBY_STACK_MIN_LIMIT = 512 * 1024, /* 512KB */
  -#endif

• RUBY_STACK_MIN_LIMIT = 64 * 1024, /* 64KB */
  RUBY_STACK_SPACE_LIMIT = 1024 * 1024
  };

--
Eric Wong
=end

[normalperson (Eric Wong)]

=begin
Eric Wong [e-mail] wrote:

Lowering RUBY_STACK_MIN_LIMIT to 64KB across the board in
thread_pthread.c seems to work fine for check, test-rubyspec,
benchmark-each.

No real code, though, and I also don't know what outside C extensions
do, but 64KB is the PTHREAD_STACK_MIN for my platform (and I've always
felt it was too high).

I was wrong about 64KB on my system 16KB is the minimum with NPTL :x

The lowest successful stack size I've been able to run is 48K, I get
stack corruption and GC failures with 44K and lower.

I've also run my Rainbows! web server[1] integration/torture test suite
with several threaded options and everything pased with 48K and didn't
notice ill effects. 44K seemed fine, too, I think, but 32K failed
Rainbows! tests miserably.

To be on the safe side with existing code/extensions and maybe some
overaggressive alloca() calls, I think 64KB is reasonable.

[1] - http://rainbows.rubyforge.org/ + http://bogomips.org/rainbows.git

--
Eric Wong
=end