From: Andi Kleen <ak@linux.intel.com>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Christoph Lameter <cl@gentwo.org>,
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 13:50:44 -0700 [thread overview]
Message-ID: <20140619205044.GX8178@tassilo.jf.intel.com> (raw)
In-Reply-To: <20140619204220.GJ4904@linux.vnet.ibm.com>
On Thu, Jun 19, 2014 at 01:42:20PM -0700, Paul E. McKenney wrote:
> 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
If we really need cond_resched() now to stop systems from dying
we did a really poor job at designing Linux. I hope it's not true,
that would be really bad and point to some severe design problems
elsewhere.
-Andi
next prev parent reply other threads:[~2014-06-19 20:50 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
2014-06-19 20:50 ` Andi Kleen [this message]
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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