Message-ID: <7798951e04091317273b1bed29@mail.gmail.com>
Date: Mon, 13 Sep 2004 19:27:02 -0500
From: hotdog day <hotdogday@gmail.com>
Reply-To: hotdog day <hotdogday@gmail.com>
To: linux-kernel@vger.kernel.org
Subject: 2.6.9-rc2 and Hyperthreading. (SMT)
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I have been testing the 2.6.9-rc1, and 2.6.9-rc2 kernel patches over
the past couple days and have been having some issues with
hyperthreading (SMT) turned on.

This problem first exhibited itself when I was testing 
2.6.9-rc2-mm2-love2. I noticed the following quirks that ONLY show
themselves with hyperthreading enabled on my 3.0C Pentium 4.

Random HARD LOCKS. No messages from the kernel. Just a good swift hard lock.

Hard locks when mounting two cdrom drives in quick succession. 

Turning off hyperthreading solves these issues.  Going back to 2.6.8.1
solves these issues.

I then tried 2.6.9-rc1 with no mm or love patches. I had the exact same issues. 

Today I downloaded the prepatch to 2.6.9-rc2 and applied it to clean
2.6.8 source. The issues are still there.

I hope someone is paying attention to the way scheduler tweaks and
changes are affecting SMT enabled kernels. I don't think anyone wants
to disable features of their hardware in order to run an optimized
scheduler.
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