Message-ID: <464A473F.1020905@Sun.COM>
Date: Tue, 15 May 2007 16:50:23 -0700
From: Joseph Kowalski <Joseph DOT Kowalski AT Sun DOT COM>
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To: cygwin AT cygwin DOT com
Subject: Re: DualCores and Current Cygwin problems
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Linda Walsh <cygwin at tlinx dot org> wrote:

>Hi, I don't claim to know what is going on, but I'm
>using a dual-core system and haven't noticed the problems you are having,
>but my processors are Intel Dual Core.  That shouldn't make a difference
>I wouldn't think.
>
>
> Joseph Kowalski wrote:
>
>1) Windows XP, fully updated;   2) Visual Studio .NET Professional (2003)
>3) Microsoft Platform SDK (2004 - *not* R2)
>4) Microsoft DirectX SDK (Summer 2004);   5) Sun Java 6 SDK (1.6.0_01)
>6) Cygwin (current).  That's it.  No additional software components.  None.
>    
>
>----
>	What do you mean by "components"?  Do you mean if you go into
>the "Add/Remove Programs", the only items I would see would be the MS SDK,
>XP "Patches", DirectX SDK, and Sun Java?  If you tell it to hide "updates",
>I'd guess you only have 3 items on your Software list?  the MS-Platform SDK,
>the DirectX SDK and the Sun Java SDK?  (Cygwin wouldn't be listed).
>
>
>	That's a pretty short list, but I assume it is a test machine
>that's off the main net and is only for testing?
>
Well, it depends upon how you look at it.  Its probably best viewed
as a build machine for building the Sun Java SDK, with emphasis
on OpenJDK.  Its a test machine in the sense that I'm starting with
a bare machine to "test" the instructions for setting up a build
environment for the JavaSDK.

That's why its a short list.  The goal is for it to be the minimal list to
build with.

I'm 2500 miles from this machine at the moment, so I'm not exactly
sure what you would see in add/remove programs.  I suspect your list
is correct, but you'ld also see Virtual Studio (which you probably missed
due to the missing <CR> above).

>
>     With this configuration, I get random "can not fork: Resource
>     temporarily unavailable" errors ... [and] "dup_proc_pipe"
>     failures, which
>     are fairly random, but tend to be understandably associated with
>     long pipes in the build process.
>
>     If I add /ONECPU to boot.ini, neatly turning my DualCore system
>     into a single core system, the failures all magically disappear. 
>
>-----
>	Using "Process Explorer" from sysinternals.com (now owned by MS), one can
>set "affinities" for processes that should limit your processes to 1 cpu.  Children
>from a processor-limited process inherit the "affinities".
>
>
>	I'm wondering -- just as a data point, if you tried building on a
>dual-core, but setting all of your cygwin processes to run on one core?
>
No, I haven't tried this, and I'm not sure exactly how I would do this.

I start with make (from cmake, for cygwin, because the cygwim make currently
has some nasty bugs related to the ol' spaces in file names situation).  
Make mostly
calls either cygwin programs *or* the Virtual Studio compilation 
system.  I'm not
sure how I'd set one group with a processor affinity and not the other.

If this experment is worth doing, give me a bit more info on what you 
expect and
I can do it when I get back to where the machine is (next week).

>
>     This would tend to indicate that there is a multi-threading issue
>     either in cygwin or in the underlying Windows XP operating
>     environment. 
>
>---
>	Sounds plausible -- all of your drivers are one's included in XP?
>  
>
Yes.

>Maybe, perversely, you could try drivers from your hardware manufacturers and
>see if they work better?  On a previous machine, I installed drivers for my
>motherboard from Intel site.
>
The drivers are basically the same.  Its a most nVidia board and the
drivers on the Microsoft site are just certified versions of the nVidia
drivers.  (Exception - the Intel network adaptor as mentioned on the
exchange with Rene - this is the Intel driver, certified by Microsoft).

>Another difference (that shouldn't make a difference)
>is the BIOS code -- I have run into BIOS code, *many* years ago, that wasn't
>reentrant --- made it a pain to work with.   But with multiple cpu's, that's a
>more challenging layer of re-entrancy than single-cpu multi-tasking/threading.
>
That would be scary.  Very, very scary...

I am down rev. (one rev.) from the current BIOS provided by ASUS,
but the newer rev only claims to expand CPU support.

>	But maybe making sure you have latest drivers from manufacturers
>even though they may not be coming with your standard WinXP install would
>help?
>
I can check the rev. on the nVidia site, and if newer, will update and
report back.

> Linda

That all said, there are a lot of threads here recently reporting this
failure symptom.  Some of the reports tend to indicate that the problem
only appeared when Cygwin was updated (then again, how many of us
visit Windows Update and forget to mention that). I tend not to think
its a chip driver revision problem.

Thanks for your help, attention and suggestions,

- Joseph Kowalski


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