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From: Linda Walsh <cygwin@tlinx.org>
To: cygwin@cygwin.com
Subject: Re: App runs 8x slower on dual core machine (with test case to replicate issue)
Date: Fri, 10 Aug 2012 03:56:00 -0000	[thread overview]
Message-ID: <50248583.30901@tlinx.org> (raw)
In-Reply-To: <loom.20120810T052639-721@post.gmane.org>

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...



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  parent reply	other threads:[~2012-08-10  3:52 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-09  8:17 Zach Saw
2012-08-09  9:22 ` Corinna Vinschen
2012-08-10  3:39   ` Zach Saw
2012-08-10  3:45     ` Daniel Colascione
2012-08-10  4:04       ` Zach Saw
2012-08-10 16:37         ` Andrew DeFaria
2012-08-11  1:14           ` Zach Saw
2012-08-11  2:32             ` Christopher Faylor
2012-08-10  3:52     ` Larry Hall (Cygwin)
2012-08-10  4:10       ` Zach Saw
2012-08-10  3:56     ` Linda Walsh [this message]
2012-08-10  4:13       ` Zach Saw
2012-08-10  6:31         ` Zach Saw
2013-01-22  4:51 ` Zach Saw
2013-01-22  8:51   ` Corinna Vinschen
2012-08-09 13:03 Zach Saw

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