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From: Dan Maas <dmaas@maasdigital.com>
To: linux-kernel@vger.kernel.org
Subject: Distinguish real vs. virtual CPUs?
Date: Mon, 21 Mar 2005 20:27:26 -0500	[thread overview]
Message-ID: <20050321202726.A7630@morpheus> (raw)

Is there a canonical way for user-space software to determine how many
real CPUs are present in a system (as opposed to HyperThreaded or
otherwise virtual CPUs)?

We have an application that for performance reasons wants to run one
process per CPU. However, on a HyperThreaded system /proc/cpuinfo
lists two CPUs, and running two processes in this case is the wrong
thing to do. (Hyperthreading ends up degrading our performance,
perhaps due to cache or bus contention).

Please CC replies.

Thanks,
Dan Maas

             reply	other threads:[~2005-03-22  1:31 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-03-22  1:27 Dan Maas [this message]
2005-03-22  1:56 ` Distinguish real vs. virtual CPUs? Dave Jones
2005-03-22 11:55   ` Dr. David Alan Gilbert
2005-03-22 15:02   ` not for amd " Tom Vier
2005-03-22  2:01 ` Daniel Andersen
2005-03-22  2:12 ` J.A. Magallon
  -- strict thread matches above, loose matches on Subject: below --
2005-03-22  4:29 Pallipadi, Venkatesh
2005-03-22 21:26 ` Bill Davidsen
2005-03-22 21:38   ` Jan Engelhardt
2005-03-23 17:52   ` Tom Vier
2005-03-23 21:32     ` Bill Davidsen

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