From: Peter Zijlstra <peterz@infradead.org>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: hpa@zytor.com, tglx@linutronix.de, mingo@elte.hu,
ak@linux.intel.com, linux-kernel@vger.kernel.org
Subject: Re: Odd performance results
Date: Tue, 12 Jul 2016 16:55:51 +0200 [thread overview]
Message-ID: <20160712145551.GU30909@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20160710144327.GX4650@linux.vnet.ibm.com>
On Sun, Jul 10, 2016 at 07:43:27AM -0700, Paul E. McKenney wrote:
> On Sun, Jul 10, 2016 at 07:17:19AM +0200, Peter Zijlstra wrote:
> >
> >
> > On 10 July 2016 06:26:39 CEST, "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> wrote:
> > >Hello!
> > >
> > >So I ran a quick benchmark which showed stair-step results. I
> > >immediately
> > >thought "Ah, this is due to CPU 0 and 1, 2 and 3, 4 and 5, and 6 and 7
> > >being threads in a core." Then I thought "Wait, this is an x86!"
> > >Then I dumped out cpu*/topology/thread_siblings_list, getting the
> > >following:
> > >
> > > cpu0/topology/thread_siblings_list: 0-1
> > > cpu1/topology/thread_siblings_list: 0-1
> > > cpu2/topology/thread_siblings_list: 2-3
> > > cpu3/topology/thread_siblings_list: 2-3
> > > cpu4/topology/thread_siblings_list: 4-5
> > > cpu5/topology/thread_siblings_list: 4-5
> > > cpu6/topology/thread_siblings_list: 6-7
> > > cpu7/topology/thread_siblings_list: 6-7
> >
> >
> > I'm guessing this is an AMD bulldozer like machine?
>
> /proc/cpuinfo thinks otherwise:
>
> processor : 0
> vendor_id : GenuineIntel
> cpu family : 6
> model : 60
> model name : Intel(R) Core(TM) i7-4710MQ CPU @ 2.50GHz
Weird, I've never seen an Intel box do that before... hpa, any idea? or
is this just one weird BIOS.
next prev parent reply other threads:[~2016-07-12 14:56 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-10 4:26 Odd performance results Paul E. McKenney
2016-07-10 5:17 ` Peter Zijlstra
2016-07-10 14:43 ` Paul E. McKenney
2016-07-12 14:55 ` Peter Zijlstra [this message]
2016-07-12 15:05 ` Paul E. McKenney
2016-07-12 17:49 ` H. Peter Anvin
2016-07-12 18:26 ` Paul E. McKenney
2016-07-12 18:51 ` Peter Zijlstra
2016-07-12 19:10 ` [CRM114spam]: " Dr. David Alan Gilbert
2016-07-12 19:59 ` Paul E. McKenney
2016-07-13 7:20 ` Ingo Molnar
2016-07-13 7:18 ` Ingo Molnar
2016-07-13 12:27 ` Henrique de Moraes Holschuh
2016-07-13 12:33 ` Peter Zijlstra
2016-07-13 14:06 ` Paul E. McKenney
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20160712145551.GU30909@twins.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=ak@linux.intel.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=paulmck@linux.vnet.ibm.com \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).