Re: scp timeout on dual-core processor

[Christopher Faylor <cgf-no-personal-reply-please at cygwin dot com>]

On Tue, May 02, 2006 at 12:26:15PM -0400, Harig, Mark wrote:
>-----Original Message-----
>From: XXXX On Behalf Of Steve Baldwin
>Sent: Tuesday, May 02, 2006 4:27 AM
>To: cygwinXXXX

Lame email clients abound.  What *is* this need to duplicate this
information in the body of a message?

>Subject: RE: scp timeout on dual-core processor
>
>(text deleted)
>
>>OK, now I don't believe my problems are related to the CPU(s).  I
>>disabled the 2nd core in the BIOS and I was still getting the problem.
>>I think it is more likely to be some nasty interaction with some piece
>>of software on this new machine.
>
>>Please ignore my previous post (at least until I do a bit more
>>investigation).
>
>Following your message, I tried this also.  I disabled two
>"performance" settings in the BIOS: one setting disabled the dual-core
>and the other setting disabled a feature that Intel is calling
>'SpeedStep'.  Even with both features disabled, the 'scp' commands
>listed in previous email messages failed.

Since this doesn't seem to be related to "dual core" (what are the
odds?) I think we need to theorize about another potential reason for
this and then act as if they were the actual cause.

Wild theory, advanced as most likely probable reason for scp hanging:

  Maybe the fan is running at such a high rpm that the vibration is
  affecting the CPU, causing it to skip over data in its pipeline.

Abbreviated cygwin discussion follows.  I've removed the embedded,
spurious From/Subject/To/Date's, the top-posting, the admonishments
against top-posting, the signatures, and the hijacking of the thread
to talk about unrelated cron problems.  This is distilled down the
the essence of a cygwin mailing list discussion:

  Yeah, it's a fan problem!

  How can Cygwin affect the fan?  Should I remove the fan?

  Should I get one of those oriental fans and fan the computer myself?

  I can't spend all of my time fanning my computer!!!

  I tried running the latest snapshot but my fan is still making a whining
  sound and I still get periodic hangs.

  This cygwin vibration must be what is causing my dog to howl, too!

  I tried removing the fan but the computer didn't run for long.  I think
  cygwin fried my computer!

  My computer is watercooled but I still have this problem.  I do have one
  fan left in the power supply.  Could that be the problem?

  I tried removing the power supply but now cygwin seems to have turned my
  computer into a boat anchor!

  I see much discussion about the fan and how it causes hangs.  Could this
  be the reason for my error when I try to configure the Svetlana 1.7?  It
  says error about NET_IPV6_IP6FRAG_TIME not found.  Then it hangs at bash.
  This works fine on linux.  Please how I care for this hang?

  Here is a random backtrace of scp when it is hung.  I would appreciate any
  advice for further in-depth debugging of this situation.

  I'm a Red Sox fan but I don't see what that has to do with Cygwin.  :-)

  No offense intended and please translate my abbreviations into something
  intelligent and insightful but mb u nd ar cndnting or u shld mv antrtica.

  I'm running cygwin in a fanless computer.  Could it be disk vibrations
  which are causing the problem?

  I tried extending my IDE cables and running the computer in another room
  from the disk drive but cygwin does not work reliably in this situation.

  Maybe it's the volume on the sound card being set too high, causing
  vibrations!  I turned down the volume on my sound card and now scp seems
  to be working fine.

  False alarm.  scp just hung for me even with the sound card volume set
  to zero.  I'm going to try disabling the sound card in the BIOS.

  That seemed to work somewhat better but I still get occasional hangs.
  I think that there could still be subsonic vibrations from the
  sound card.  I'm going to try removing the sound card entirely.  I'll
  wrap it in aluminum foil and bury it in the back yard, just to be safe.

  I removed (and buried) the sound card and now scp seems to be working reliably!!!
  I can't believe that cygwin requires you to remove a sound card if you want
  to use scp.  What about people in apartments?  They may not be able to bury
  their sound cards easily!

  How can any software product seriously be affected by disk drive vibrations?
  This is a serious problem!  Is anyone actually looking into it?  If cygwin wants
  to be taken seriously, it really needs to fix this disk problem!

  I think someone needs to put a microphone next the the CPU and get real data
  here.  That's the only way we'll solve this vibration problem.

  Has anyone put some kind of microphone near the CPU?  It seems like we need
  to see what kind of vibrations are causing this problem.

  Please unsuscribe.

cgf