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From: Joel Schopp <jschopp@austin.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>,
	linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
	ego@in.ibm.com
Subject: Re: [PATCHv3 2/2] powerpc: implement arch_scale_smt_power for Power7
Date: Fri, 29 Jan 2010 12:34:47 -0600	[thread overview]
Message-ID: <4B632A47.4070103@austin.ibm.com> (raw)
In-Reply-To: <1264760027.4283.2164.camel@laptop>


> That said, I'm still not entirely convinced I like this usage of
> cpupower, its supposed to be a normalization scale for load-balancing,
> not a placement hook.
>   
Even if you do a placement hook you'll need to address it in the load 
balancing as well.  Consider a single 4 thread SMT core with 4 running 
tasks.  If 2 of them exit the remaining 2 will need to be load balanced 
within the core in a way that takes into account the dynamic nature of 
the thread power.  This patch does that.
> I'd be much happier with a SD_GROUP_ORDER or something like that, that
> works together with SD_PREFER_SIBLING to pack active tasks to cpus in
> ascending group order.
>
>   
I don't see this load-balancing patch as mutually exclusive with a patch 
to fix placement.  But even if it is a mutually exclusive solution there 
is no reason we can't fix things now with this patch and then later take 
it out when it's fixed another way.  This patch series is 
straightforward, non-intrusive, and without it the scheduler is broken 
on this processor. 

  reply	other threads:[~2010-01-29 18:34 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-20 20:00 [PATCH 0/2] sched: arch_scale_smt_powers Joel Schopp
2010-01-20 20:02 ` [PATCH 1/2] sched: Fix the place where group powers are updated Joel Schopp
2010-01-26 23:28   ` [PATCHv2 1/2] sched: enable ARCH_POWER Joel Schopp
2010-01-28 23:20     ` [PATCHv3 " Joel Schopp
2010-02-05 20:57       ` [PATCHv4 " Joel Schopp
2010-01-20 20:04 ` [PATCH 2/2] powerpc: implement arch_scale_smt_power for Power7 Joel Schopp
2010-01-20 20:48   ` Peter Zijlstra
2010-01-20 21:58     ` Michael Neuling
2010-01-20 22:44     ` Joel Schopp
2010-01-21  8:27       ` Peter Zijlstra
2010-01-20 21:04   ` Michael Neuling
2010-01-20 22:09     ` Joel Schopp
2010-01-24  3:00       ` Benjamin Herrenschmidt
2010-01-25 17:50         ` Joel Schopp
2010-01-26  4:23           ` Benjamin Herrenschmidt
2010-01-20 21:33   ` Benjamin Herrenschmidt
2010-01-20 22:36     ` Joel Schopp
2010-01-26 23:28   ` [PATCHv2 " Joel Schopp
2010-01-27  0:52     ` Benjamin Herrenschmidt
2010-01-28 22:39       ` Joel Schopp
2010-01-29  1:23         ` Benjamin Herrenschmidt
2010-01-28 23:20     ` [PATCHv3 " Joel Schopp
2010-01-28 23:24       ` Joel Schopp
2010-01-29  1:23         ` Benjamin Herrenschmidt
2010-01-29 10:13           ` Peter Zijlstra
2010-01-29 18:34             ` Joel Schopp [this message]
2010-01-29 18:41           ` Joel Schopp
2010-02-05 20:57         ` [PATCHv4 " Joel Schopp
2010-02-14 10:12           ` Peter Zijlstra
2010-02-17 22:20             ` Michael Neuling
2010-02-18 13:17               ` Peter Zijlstra
2010-02-18 13:19                 ` Peter Zijlstra
2010-02-18 16:28                 ` Joel Schopp
2010-02-18 17:08                   ` Peter Zijlstra
2010-02-19  6:05                 ` Michael Neuling
2010-02-19 10:01                   ` Peter Zijlstra
2010-02-19 11:01                     ` Michael Neuling
2010-02-23  6:08                       ` Michael Neuling
2010-02-23 16:24                         ` Peter Zijlstra
2010-02-23 16:30                           ` Peter Zijlstra
2010-02-24  6:07                           ` Michael Neuling
2010-02-24 11:13                             ` Michael Neuling
2010-02-24 11:58                               ` Michael Neuling
2010-02-27 10:21                               ` Michael Neuling
2010-03-02 14:44                                 ` Peter Zijlstra
2010-03-04 22:28                                   ` Michael Neuling
2010-01-29 12:25       ` [PATCHv3 " Gabriel Paubert
2010-01-29 16:26         ` Joel Schopp
2010-01-26 23:27 ` [PATCHv2 0/2] sched: arch_scale_smt_powers v2 Joel Schopp
2010-01-28 23:20   ` [PATCHv3 0/2] sched: arch_scale_smt_powers Joel Schopp
2010-02-05 20:57     ` [PATCHv4 " Joel Schopp

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