From: maxime.ripard@free-electrons.com (Maxime Ripard)
To: kernelnewbies@lists.kernelnewbies.org
Subject: Get local CPU id
Date: Mon, 9 Mar 2015 13:59:47 +0100 [thread overview]
Message-ID: <20150309125947.GQ5085@lukather> (raw)
In-Reply-To: <208859.1425853847@turing-police.cc.vt.edu>
On Sun, Mar 08, 2015 at 06:30:47PM -0400, Valdis.Kletnieks at vt.edu wrote:
> On Sun, 08 Mar 2015 22:49:00 +0100, Maxime Ripard said:
>
> > On Sun, Mar 08, 2015 at 10:06:23PM +0300, Matwey V. Kornilov wrote:
>
> > > I would like to somehow obtain local CPU core ID in the interrupt
> > > handler function. I want to see how my interruptions are distributed
> > > among different CPU cores under different conditions.
>
> > > How should I do that?
> >
> > To answer strictly your question, like Nick said, smp_processor_id()
> > will work fine.
> >
> > However, you can do exactly what you want be reading /proc/interrupts,
> > that already provide the informations you are looking for.
>
> Clarification: /proc/interrupts will give userspace that information.
> It is *not* recommended you try to read it from kernel space, much less
> from an interrupt context... :)
Hmmm, yes, it was a little too obvious in my mind :)
Thanks for the clarification!
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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next prev parent reply other threads:[~2015-03-09 12:59 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-08 19:06 Get local CPU id Matwey V. Kornilov
2015-03-08 20:41 ` Nicholas Krause
2015-03-08 21:49 ` Maxime Ripard
2015-03-08 22:03 ` Nicholas Krause
2015-03-08 22:30 ` Valdis.Kletnieks at vt.edu
2015-03-08 23:10 ` Nicholas Krause
2015-03-09 14:39 ` Maxime Ripard
2015-03-09 12:59 ` Maxime Ripard [this message]
2015-03-09 0:37 ` Anish Kumar
2015-03-09 0:52 ` Nicholas Krause
2015-03-09 15:35 ` Matwey V. Kornilov
2015-03-09 16:26 ` Jeff Haran
2015-03-09 17:42 ` Nick Krause
2015-03-09 18:10 ` Valdis.Kletnieks at vt.edu
2015-03-09 20:05 ` Nicholas Krause
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