From: Shyouhei Urabe <shyouhei@...>
Date: 2011-02-28T12:54:03+09:00
Subject: [ruby-core:35389] [Backport87 - Backport #2553] [Open] Fix pthreads slowness by eliminating unnecessary sigprocmask calls


Issue #2553 has been updated by Shyouhei Urabe.

Tracker changed from Bug to Backport
Status changed from Closed to Open
% Done changed from 100 to 0

As of 1.8.7-334 this issue is reopened because the proposed fix broke binary compatibility. cf [ruby-dev:43152]
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Backport #2553: Fix pthreads slowness by eliminating unnecessary sigprocmask calls
http://redmine.ruby-lang.org/issues/2553

Author: Dan Peterson
Status: Open
Priority: Low
Assignee: Shyouhei Urabe
Category: core
Target version: 
ruby -v: ruby 1.8.7 (2009-12-24 patchlevel 248) [i686-linux]


 This is a bug report for what's described here:
 
 http://timetobleed.com/fix-a-bug-in-rubys-configurein-and-get-a-30-performance-boost/
 
 Matz says here that this should already be fixed in 1.8.7:
 
 http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-core/23583
 
 But it does not appear to be. Example with 1.8.7-p248:
 
 # apply patch from above link
 % make distclean
 % ./configure --enable-pthread
 % make
 % time ./ruby -e '1_000_000.times { x = 2 ** 256 }'
 ./ruby -e '1_000_000.times { x = 2 ** 256 }'  1.45s user 0.34s system 99% cpu 1.809 total
 % strace ./ruby -e '1_000.times { x = 2 ** 256 }' 2>&1 | grep -c sigproc 
 1009
 % make distclean
 % ./configure --disable-ucontext --enable-pthread
 % make
 % time ./ruby -e '1_000_000.times { x = 2 ** 256 }'
 ./ruby -e '1_000_000.times { x = 2 ** 256 }'  1.16s user 0.00s system 99% cpu 1.171 total
 % strace ./ruby -e '1_000.times { x = 2 ** 256 }' 2>&1 | grep -c sigproc 
 3
 
 % ./ruby -v
 ruby 1.8.7 (2009-12-24 patchlevel 248) [i686-linux]


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