From: Mike Galbraith <efault@gmx.de>
To: Christopher Lameter <cl@linux.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Frederic Weisbecker <fweisbec@gmail.com>,
Luiz Capitulino <lcapitulino@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Chris Metcalf <cmetcalf@mellanox.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>, Rik van Riel <riel@redhat.com>,
Wanpeng Li <kernellwp@gmail.com>
Subject: Re: [RFC PATCH 7/9] housekeeping: Use own boot option, independant from nohz
Date: Wed, 16 Aug 2017 20:00:44 +0200 [thread overview]
Message-ID: <1502906444.4945.65.camel@gmx.de> (raw)
In-Reply-To: <alpine.DEB.2.20.1708151122090.2578@nuc-kabylake>
On Tue, 2017-08-15 at 11:26 -0500, Christopher Lameter wrote:
> On Tue, 15 Aug 2017, Mike Galbraith wrote:
>
> > On Tue, 2017-08-15 at 10:52 -0500, Christopher Lameter wrote:
> > > On Tue, 15 Aug 2017, Paul E. McKenney wrote:
> > >
> > > > Don't the HPC guys just disable idle_balance(), or am I out of date again?
> > >
> > > Ummm.. Why does idle management matter when your goal is to keep all
> > > processor busy working at maximum throughput?
> >
> > If you _never_ idle, you never have to worry about it. Is 100% CPU
> > until the end of time all there is to HPC?
>
> Most of the time that is true for HPC loads. They may also go through a
> I/O throughput constrained processing phase or synchronization phase where
> idle activity occurs.
That synchronization is what I tend to get all hung up on pondering HPC
vs RT terminology. Care and feeding of parallel pipelines has got to
be loaded to the gills with synchronization (intermediate math results
etc), rendering the sum event driven.
Doesn't matter, both acronyms reduce to latency intolerant.
-Mike
next prev parent reply other threads:[~2017-08-16 18:01 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-21 13:21 [RFC PATCH 0/9] Introduce housekeeping subsystem Frederic Weisbecker
2017-07-21 13:21 ` [RFC PATCH 1/9] housekeeping: Move housekeeping related code to its own file Frederic Weisbecker
2017-07-21 13:21 ` [RFC PATCH 2/9] watchdog: Use housekeeping_cpumask() instead of ad-hoc version Frederic Weisbecker
2017-07-21 13:21 ` [RFC PATCH 3/9] housekeeping: Provide a dynamic off-case to housekeeping_any_cpu() Frederic Weisbecker
2017-07-21 13:21 ` [RFC PATCH 4/9] housekeeping: Make housekeeping cpumask private Frederic Weisbecker
2017-07-21 13:21 ` [RFC PATCH 5/9] housekeeping: Use its own static key Frederic Weisbecker
2017-07-21 13:21 ` [RFC PATCH 6/9] housekeeping: Rename is_housekeeping_cpu to housekeeping_cpu Frederic Weisbecker
2017-07-21 13:21 ` [RFC PATCH 7/9] housekeeping: Use own boot option, independant from nohz Frederic Weisbecker
2017-08-11 19:09 ` Luiz Capitulino
2017-08-12 14:10 ` Frederic Weisbecker
2017-08-13 15:13 ` Luiz Capitulino
2017-08-14 17:01 ` Frederic Weisbecker
2017-08-14 17:34 ` Luiz Capitulino
2017-08-14 18:29 ` Mike Galbraith
2017-08-15 13:07 ` Frederic Weisbecker
2017-08-15 15:15 ` Mike Galbraith
2017-08-15 15:30 ` Paul E. McKenney
2017-08-15 15:52 ` Christopher Lameter
2017-08-15 15:57 ` Mike Galbraith
2017-08-15 16:26 ` Christopher Lameter
2017-08-16 18:00 ` Mike Galbraith [this message]
2017-08-15 15:53 ` Mike Galbraith
2017-07-21 13:21 ` [RFC PATCH 8/9] housekeeping: Move it under own config, independant from NO_HZ Frederic Weisbecker
2017-07-21 13:21 ` [RFC PATCH 9/9] workqueue: Affine unbound workqueues to housekeeping cpumask Frederic Weisbecker
2017-07-21 19:48 ` [RFC PATCH 0/9] Introduce housekeeping subsystem Chris Metcalf
2017-08-10 12:54 ` Frederic Weisbecker
2017-08-10 13:57 ` Chris Metcalf
2017-08-11 6:36 ` Mike Galbraith
2017-08-11 15:01 ` Frederic Weisbecker
2017-08-11 19:22 ` Luiz Capitulino
2017-08-11 15:08 ` Chris Metcalf
2017-08-11 15:35 ` Christopher Lameter
2017-08-11 15:50 ` Chris Metcalf
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