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From: Arjan van de Ven <>
To: Brian McGrew <>
Subject: Re: Threading...
Date: Fri, 19 Jan 2007 19:55:41 +0100	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

On Fri, 2007-01-19 at 10:43 -0800, Brian McGrew wrote:
> I have a very interesting question about something that we're seeing
> happening with threading between Fedora Core 3 and Fedora Core 5.  Running
> on Dell PowerEdge 1800 Hardware with a Xeon processor with hyper-threading
> turned on.  Both systems are using a kernel (MVP al la special).
> We have a multithreaded application that starts two worker threads.  On
> Fedora Core 3 both of these we use getpid() to get the PID of the thread and
> then use set_afinity to assign each thread to it's own CPU.  Both threads
> run almost symmetrically even on their given CPU watching the system
> monitor.

this is odd; even in FC3 getpid() is supposed to return the process ID
not the thread ID

> What am I missing?  What do I need to do in FC5 or the kernel or the
> threading library to get my threads to run in symmetric parallel again???

you should fix the app to use something like pthread_self() instead...
(or the highly unportable gettid() but that would just be horrible)

if you want to mail me at work (you don't), use arjan (at)
Test the interaction between Linux and your BIOS via

  reply	other threads:[~2007-01-19 18:56 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-19 18:43 Threading Brian McGrew
2007-01-19 18:55 ` Arjan van de Ven [this message]
2007-01-19 19:01   ` Threading Brian McGrew
2007-01-19 19:23     ` Threading Arjan van de Ven
2007-01-19 21:26     ` Threading Bill Davidsen
2007-01-20  1:18   ` Threading J.A. Magallón

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