X-Recipient: archive-cygwin@delorie.com
X-SWARE-Spam-Status: No, hits=-1.7 required=5.0	tests=AWL,BAYES_00,KHOP_THREADED,T_RP_MATCHES_RCVD
X-Spam-Check-By: sourceware.org
Message-ID: <50248583.30901@tlinx.org>
Date: Thu, 09 Aug 2012 20:52:35 -0700
From: Linda Walsh <cygwin@tlinx.org>
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.8.1.24) Gecko/20100228 Lightning/0.9 Thunderbird/2.0.0.24 Mnenhy/0.7.6.666
MIME-Version: 1.0
To: cygwin@cygwin.com
Subject: Re: App runs 8x slower on dual core machine (with test case to replicate issue)
References: <CAFY+UmUspDUbo4JaW9NDG1zf1oY2rgS5g3zO7q-qnby3tJqrSg@mail.gmail.com> <20120809081720.GQ31757@calimero.vinschen.de> <loom.20120810T052639-721@post.gmane.org>
In-Reply-To: <loom.20120810T052639-721@post.gmane.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-IsSubscribed: yes
Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm
List-Id: <cygwin.cygwin.com>
List-Subscribe: <mailto:cygwin-subscribe@cygwin.com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin@cygwin.com>
List-Help: <mailto:cygwin-help@cygwin.com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner@cygwin.com
Mail-Followup-To: cygwin@cygwin.com
Delivered-To: mailing list cygwin@cygwin.com

Zach Saw wrote:
> Corinna Vinschen <corinna-cygwin <at> cygwin.com> writes: 
>> Thanks for the testcase, but... would you mind to change it to take the
>> boost lib out of the picture, by using just plain pthread functions, if
>> possible in plain C?
> 
> Apparently someone else has already encountered similar problems in 
> cygwin perl 
> (http://www.nntp.perl.org/group/perl.perl5.porters/2011/07/msg174491.html)
--------------
--
I can confirm the perl test case:

Using the referenced prog:
on Linux:
cyg-perl-thread-test.pl
This is perl 5, version 14, subversion 2 (v5.14.2) built for 
x86_64-linux-thread-multi
Processing 10 tasks in 1 threads completed in 0.468952secs
Processing 10 tasks in 4 threads completed in 0.156822secs
cat /proc/cpuinfo/Hz|sort |uniq
model name      : Intel(R) Xeon(R) CPU           X5660  @ 2.80GHz
cpu MHz         : 1596.000


On Cygwin:
This is perl 5, version 14, subversion 2 (v5.14.2) built for 
cygwin-thread-multi-64int
Processing 10 tasks in 1 threads completed in 1.060806secs
Processing 10 tasks in 4 threads completed in 9.640635secs
/Users/law> cat /proc/cpuinfo|grep Hz|sort -r |uniq
model name      : Intel(R) Xeon(R) CPU           X5680  @ 3.33GHz
cpu MHz         : 3325

---
Note -- neither of my cpu's have "HT" enabled.. So in both
cases 'threads' must use separate processes...



--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple