From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: peterz@infradead.org, hpa@zytor.com, tglx@linutronix.de,
mingo@elte.hu, ak@linux.intel.com
Cc: linux-kernel@vger.kernel.org
Subject: Odd performance results
Date: Sat, 9 Jul 2016 21:26:39 -0700 [thread overview]
Message-ID: <20160710042639.GA4068@linux.vnet.ibm.com> (raw)
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
Is this now expected behavior or a fluke of my particular laptop? Here is
hoping for expected behavior, as it makes NUMA locality the default for
a great many workloads.
Enlightenment?
Thanx, Paul
next reply other threads:[~2016-07-10 4:26 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-10 4:26 Paul E. McKenney [this message]
2016-07-10 5:17 ` Odd performance results Peter Zijlstra
2016-07-10 14:43 ` Paul E. McKenney
2016-07-12 14:55 ` Peter Zijlstra
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
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