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Date: Sun, 20 Nov 2011 15:21:16 -0700
From: Stephen John Smoogen <smooge@...il.com>
To: john-users@...ts.openwall.com
Subject: Re: OpenMP not using all threads

On 19 November 2011 21:35, Stephen Reese <rsreese@...il.com> wrote:
> On Sat, Nov 19, 2011 at 11:13 PM, Solar Designer <solar@...nwall.com> wrote:
>> On Sat, Nov 19, 2011 at 10:38:30PM -0500, Stephen Reese wrote:

> I confirmed that there are 8 threads (4 cores) in the processor
> http://ark.intel.com/products/40201/Intel-Xeon-Processor-L5520-%288M-Cache-2_26-GHz-5_86-GTs-Intel-QPI%29
> I asked Linode and their response was there are four cores hence I am
> only going to see four entries in /proc/cpuinfo. Maybe they have
> hyper-threading disabled (I asked and did not receive a specific
> response).

Most (if not all) Linode systems are virtualized systems which I
believe normally don't do well with hyperthreading. For high compute
virtualization you usually need systems with cpu-pinning and such to
get the performance that you get from bare metal.

-- 
Stephen J Smoogen.
"The core skill of innovators is error recovery, not failure avoidance."
Randy Nelson, President of Pixar University.
"Let us be kind, one to another, for most of us are fighting a hard
battle." -- Ian MacLaren

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