From: Mikael Pettersson <mikpe@csd.uu.se>
To: Dave Jones <davej@codemonkey.org.uk>
Cc: jamesclv@us.ibm.com, Jason Lunz <lunz@falooley.org>,
linux-kernel@vger.kernel.org
Subject: Re: detecting hyperthreading in linux 2.4.19
Date: Fri, 10 Jan 2003 12:19:07 +0100 [thread overview]
Message-ID: <15902.44075.649993.9488@harpo.it.uu.se> (raw)
In-Reply-To: <20030110110547.GC29190@codemonkey.org.uk>
Dave Jones writes:
> On Fri, Jan 10, 2003 at 08:05:07AM +0100, Mikael Pettersson wrote:
>
> > If the kernel has sched_setaffinity() or some other way of binding a process
> > to a given CPU (as numbered by the kernel, which may or may not be related
> > to any physical CPU numbers), then this will do it: execute CPUID on each
> > CPU and check the initial APIC ID field. If you find one that's non-zero,
> > then HT is enabled.
>
> That's a horrible way of reimplementing /dev/cpu/x/cpuid 8-)
True. I forgot about that interface since I personally never configure or use it.
So this answers the original question. Just access /dev/cpu/$CPU/cpuid
for all (accessible) values of $CPU.
next prev parent reply other threads:[~2003-01-10 11:10 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-01-09 20:02 Jason Lunz
2003-01-09 21:37 ` James Cleverdon
2003-01-09 21:54 ` John Bradford
2003-01-10 0:16 ` James Cleverdon
2003-01-10 0:58 ` Mike Dresser
2003-01-09 21:57 ` Jason Lunz
2003-01-10 12:29 ` Mark Hounschell
2003-01-10 7:05 ` Mikael Pettersson
2003-01-10 11:05 ` Dave Jones
2003-01-10 11:19 ` Mikael Pettersson [this message]
2003-01-10 0:20 ` Dave Jones
2003-01-09 22:29 Kamble, Nitin A
2003-01-09 23:26 Pallipadi, Venkatesh
2003-01-10 8:16 Pallipadi, Venkatesh
2003-01-10 8:43 ` Mikael Pettersson
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