Feature #4614

[RFC/PATCH] thread_pthread.c: lower RUBY_STACK_MIN_LIMIT to 64K

Added by Eric Wong over 4 years ago. Updated over 2 years ago.

[ruby-core:35895]
Status:Closed
Priority:Normal
Assignee:Koichi Sasada

Description

=begin
The patch (committed) for Issue #4568 made this change possible.

Lowering stack size allows users on memory-constrained 32-bit
machines to spawn more native threads (which are easier (IMHO)
to use than Fibers).

Setting RUBY_STACK_MIN_LIMIT to 48K seems to work even with
check, test-rubyspec, and benchmark-each targets. However, I'm
keeping it at 64K since that is what Symbian uses, so maybe
there's some code paths that need 64K.

I started experiencing failures with the Ruby tests with 44K on
x86_64, so 44K is definitely not safe. Much more effort would
be required to make Ruby work with smaller stacks than 48K.

Also pullable via git: git pull git://bogomips.org/ruby.git stack-reduce

=end

0001-thread_pthread.c-lower-RUBY_STACK_MIN_LIMIT-to-64K.patch Magnifier (1.34 KB) Eric Wong, 04/26/2011 08:56 AM

History

#1 Updated by Koichi Sasada about 4 years ago

  • Assignee set to Koichi Sasada

GC eats large stack size if there are nested object (deep nested array and so on). I'm not sure but I think this is why we allocate 512KB for stack.

Any comments?

I think that Thread.new should accept stack size.

#2 Updated by Eric Wong about 4 years ago

Koichi Sasada redmine@ruby-lang.org wrote:

GC eats large stack size if there are nested object (deep nested array
and so on). I'm not sure but I think this is why we allocate 512KB
for stack.

Good point. I didn't think of that (rare case for me). We would need a
non-recursive implementation of gc_mark_children.

A simpler idea would be a dedicated marking thread with a deeper stack;
but I think that's ugly.

Any comments?

I think that Thread.new should accept stack size.

I'm not sure what the API would be. While it would help me, I think it
would be difficult to use and too low level for Ruby.

Meanwhile I can rebuild Ruby or use a trivial LD_PRELOAD:
http://yhbt.net/libministack.c

--
Eric Wong

#3 Updated by Shyouhei Urabe over 3 years ago

  • Status changed from Open to Assigned

#4 Updated by Koichi Sasada almost 3 years ago

  • Priority changed from 3 to 5
  • Status changed from Assigned to Feedback

Ad-hoc solution, but environment variable (such as RUBY_THREAD_MACHINE_STACK_SIZE) is enough for this issue?

#5 Updated by Eric Wong almost 3 years ago

"ko1 (Koichi Sasada)" redmine@ruby-lang.org wrote:

Ad-hoc solution, but environment variable (such as
RUBY_THREAD_MACHINE_STACK_SIZE) is enough for this issue?

I think environment variable is too ugly, but it's your (or matz's)
choice to support it.

Also, it seems the recursive structure problem with gc_mark_children()
is gone since r37075.

Probably better to discuss #6695 instead.

#6 Updated by Yusuke Endoh almost 3 years ago

ko1, what's the status?

Too many 2.0.0 tickets, especially big task ones, are assigned to ko1. ko1, please decide your priorities.

Welcome to volunteer for helping him.

Yusuke Endoh mame@tsg.ne.jp

#7 Updated by Koichi Sasada almost 3 years ago

Priority: High.

#8 Updated by Koichi Sasada over 2 years ago

  • Priority changed from 5 to Normal

I add environment variable at r38479.

    - RUBY_THREAD_VM_STACK_SIZE: vm stack size used at thread creation.
      default: 128KB (32bit CPU) or 256KB (64bit CPU).
    - RUBY_THREAD_MACHINE_STACK_SIZE: machine stack size used at thread
      creation. default: 512KB or 1024KB.
    - RUBY_FIBER_VM_STACK_SIZE: vm stack size used at fiber creation.
      default: 64KB or 128KB.
    - RUBY_FIBER_MACHINE_STACK_SIZE: machine stack size used at fiber
      creation. default: 256KB or 256KB.

I want to ask feedback about this default setting.

#9 Updated by Eric Wong over 2 years ago

"ko1 (Koichi Sasada)" redmine@ruby-lang.org wrote:

I add environment variable at r38479.

Thanks!

Btw, you put a giant "if false" around test/ruby/test_fiber.rb
with that commit. Was that intentional?

I want to ask feedback about this default setting.

I'm fine with the current defaults (including the r38592 update)

#10 Updated by Koichi Sasada over 2 years ago

  • Status changed from Feedback to Closed

Sorry I missed your comment.
And the `if false' sentences may be removed.

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