From: Maximilian Gass <redmine@...>
Date: 2009-07-28T04:12:13+09:00
Subject: [ruby-core:24576] [Bug #1820] Always spawns a thread that loops on the futex syscall

Bug #1820: Always spawns a thread that loops on the futex syscall
http://redmine.ruby-lang.org/issues/show/1820

Author: Maximilian Gass
Status: Open, Priority: Normal
Category: core
ruby -v: ruby 1.9.1p0 (2009-01-30 revision 21907) [x86_64-linux]

Starting with Ruby 1.9, every Ruby process starts two threads. 
One of these is looping on the futex syscall all the time. 
I have attached an strace log of irb.

Ruby 1.9.0 had the same problem, but it was a different syscall.

I tested this on Debian GNU/Linux, but the problem also existed on Gentoo Linux. 
It still exists with the recent Ruby 1.9.2 preview release:


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