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From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Christoph Lameter <cl@gentwo.org>
Cc: Andi Kleen <ak@linux.intel.com>,
	Dave Hansen <dave.hansen@intel.com>,
	LKML <linux-kernel@vger.kernel.org>,
	Josh Triplett <josh@joshtriplett.org>,
	"Chen, Tim C" <tim.c.chen@intel.com>
Subject: Re: [bisected] pre-3.16 regression on open() scalability
Date: Thu, 19 Jun 2014 13:42:20 -0700	[thread overview]
Message-ID: <20140619204220.GJ4904@linux.vnet.ibm.com> (raw)
In-Reply-To: <alpine.DEB.2.11.1406191531020.4002@gentwo.org>

On Thu, Jun 19, 2014 at 03:31:56PM -0500, Christoph Lameter wrote:
> On Thu, 19 Jun 2014, Paul E. McKenney wrote:
> 
> > That is a separate issue, but unnecessary calls to cond_resched()
> > should of course be removed -- no argument there.
> 
> It looks like we are fighting higher latencies by adding calls in most of
> the critical sections which will in turn increase the latencies that we
> are trying to reduce.

That is on battle in a larger war.  Another battle is to keep big systems
from choking and dying.  We need to win both battles, though I understand
that you are focused primarily on latency reduction.  I don't get that
luxury because RCU is used across the board.

							Thanx, Paul


  reply	other threads:[~2014-06-19 20:44 UTC|newest]

Thread overview: 49+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-13 20:04 [bisected] pre-3.16 regression on open() scalability Dave Hansen
2014-06-13 22:45 ` Paul E. McKenney
2014-06-13 23:35   ` Dave Hansen
2014-06-14  2:03     ` Paul E. McKenney
2014-06-17 23:10   ` Dave Hansen
2014-06-18  0:00     ` Josh Triplett
2014-06-18  0:15     ` Andi Kleen
2014-06-18  1:04       ` Paul E. McKenney
2014-06-18  2:27         ` Andi Kleen
2014-06-18  4:47           ` Paul E. McKenney
2014-06-18 12:40             ` Andi Kleen
2014-06-18 12:56               ` Paul E. McKenney
2014-06-18 14:29       ` Christoph Lameter
2014-06-18  0:18     ` Paul E. McKenney
2014-06-18  6:33       ` Dave Hansen
2014-06-18 12:58         ` Paul E. McKenney
2014-06-18 17:36           ` Dave Hansen
2014-06-18 20:30             ` Paul E. McKenney
2014-06-18 23:51               ` Paul E. McKenney
2014-06-19  1:42                 ` Andi Kleen
2014-06-19  2:13                   ` Paul E. McKenney
2014-06-19  2:29                     ` Paul E. McKenney
2014-06-19  2:50                     ` Mike Galbraith
2014-06-19  4:19                       ` Paul E. McKenney
2014-06-19  3:38                     ` Andi Kleen
2014-06-19  4:19                       ` Paul E. McKenney
2014-06-19  5:24                         ` Mike Galbraith
2014-06-19 18:14                           ` Paul E. McKenney
2014-06-19  4:52                       ` Eric Dumazet
2014-06-19  5:23                         ` Paul E. McKenney
2014-06-19 14:42                   ` Christoph Lameter
2014-06-19 18:09                     ` Paul E. McKenney
2014-06-19 20:31                       ` Christoph Lameter
2014-06-19 20:42                         ` Paul E. McKenney [this message]
2014-06-19 20:50                           ` Andi Kleen
2014-06-19 21:03                             ` Paul E. McKenney
2014-06-19 21:13                           ` Christoph Lameter
2014-06-19 21:16                             ` Christoph Lameter
2014-06-19 21:32                               ` josh
2014-06-19 23:07                                 ` Paul E. McKenney
2014-06-20 15:20                                   ` Christoph Lameter
2014-06-20 15:38                                     ` Paul E. McKenney
2014-06-20 16:07                                       ` Christoph Lameter
2014-06-20 16:30                                         ` Paul E. McKenney
2014-06-20 17:39                                           ` Dave Hansen
2014-06-20 18:15                                             ` Paul E. McKenney
2014-06-18 21:48 ` Paul E. McKenney
2014-06-18 22:03   ` Dave Hansen
2014-06-18 22:52     ` Paul E. McKenney

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