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From: Dave Hansen <dave.hansen@intel.com>
To: paulmck@linux.vnet.ibm.com
Cc: linux-kernel@vger.kernel.org, mingo@kernel.org,
	laijs@cn.fujitsu.com, dipankar@in.ibm.com,
	akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
	josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org,
	rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
	dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com,
	ak@linux.intel.com, cl@gentwo.org, umgwanakikbuti@gmail.com
Subject: Re: [PATCH tip/core/rcu] Reduce overhead of cond_resched() checks for RCU
Date: Mon, 23 Jun 2014 17:20:30 -0700	[thread overview]
Message-ID: <53A8C44E.7050000@intel.com> (raw)
In-Reply-To: <20140624001519.GO4603@linux.vnet.ibm.com>

On 06/23/2014 05:15 PM, Paul E. McKenney wrote:
> Just out of curiosity, how many CPUs does your system have?  80?
> If 160, looks like something bad is happening at 80.

80 cores, 160 threads.  >80 processes/threads is where we start using
the second thread on the cores.  The tasks are also pinned to
hyperthread pairs, so they disturb each other, and the scheduler moves
them between threads on occasion which causes extra noise.

  reply	other threads:[~2014-06-24  0:20 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-21  2:59 [PATCH tip/core/rcu] Reduce overhead of cond_resched() checks for RCU Paul E. McKenney
2014-06-21  4:29 ` Josh Triplett
2014-06-21  6:06   ` Paul E. McKenney
2014-06-23 13:53     ` Christoph Lameter
2014-06-23 15:26       ` Paul E. McKenney
2014-06-23  6:26 ` Peter Zijlstra
2014-06-23 13:33   ` Paul E. McKenney
2014-06-23 13:51   ` Christoph Lameter
2014-06-23 16:45     ` Paul E. McKenney
2014-06-23 15:49   ` Andi Kleen
2014-06-23 16:43     ` Paul E. McKenney
2014-06-23 17:19       ` Andi Kleen
2014-06-23 17:42         ` Paul E. McKenney
2014-06-23 16:55 ` Dave Hansen
2014-06-23 17:16   ` Paul E. McKenney
2014-06-23 17:34     ` Dave Hansen
2014-06-23 17:17   ` Dave Hansen
2014-06-23 18:09     ` Paul E. McKenney
2014-06-23 23:30       ` Dave Hansen
2014-06-24  0:15         ` Paul E. McKenney
2014-06-24  0:20           ` Dave Hansen [this message]
2014-06-24  0:39             ` Paul E. McKenney
2014-06-24 16:18               ` Dave Hansen
2014-06-24 20:43               ` Dave Hansen
2014-06-24 21:15                 ` Paul E. McKenney

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