From: Catalin Marinas <catalin.marinas@arm.com>
To: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
"tony.luck@intel.com" <tony.luck@intel.com>,
"len.brown@intel.com" <len.brown@intel.com>,
"alex.shi@intel.com" <alex.shi@intel.com>,
"linux@arm.linux.org.uk" <linux@arm.linux.org.uk>,
"corbet@lwn.net" <corbet@lwn.net>,
Arjan van de Ven <arjan@linux.intel.com>,
"mingo@kernel.org" <mingo@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"cmetcalf@tilera.com" <cmetcalf@tilera.com>,
"chander.kashyap@linaro.org" <chander.kashyap@linaro.org>,
"linaro-kernel@lists.linaro.org" <linaro-kernel@lists.linaro.org>,
"preeti@linux.vnet.ibm.com" <preeti@linux.vnet.ibm.com>,
"paulmck@linux.vnet.ibm.com" <paulmck@linux.vnet.ibm.com>,
"pjt@google.com" <pjt@google.com>,
Morten Rasmussen <Morten.Rasmussen@arm.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [RFC PATCH v3 3/6] sched: pack small tasks
Date: Wed, 27 Mar 2013 17:37:42 +0000 [thread overview]
Message-ID: <20130327173742.GA17642@arm.com> (raw)
In-Reply-To: <alpine.LFD.2.03.1303271314240.1372@syhkavp.arg>
On Wed, Mar 27, 2013 at 05:18:53PM +0000, Nicolas Pitre wrote:
> On Wed, 27 Mar 2013, Catalin Marinas wrote:
>
> > So if the above works, the scheduler guys can mandate that little CPUs
> > are always first and for ARM it would be a matter of getting the right
> > CPU topology in the DT (independent of what hw vendors think of CPU
> > topology) and booting Linux on CPU 4 etc.
>
> Just a note about that: if the scheduler mandates little CPUs first,
> that should _not_ have any implications on the DT content. DT is not
> about encoding Linux specific implementation details. It is simple
> enough to tweak the CPU logical map at run time when enumeratiing CPUs.
You are right, though a simpler way (hack) to tweak the cpu_logical_map
is to change the DT ;).
But the problem is that the kernel doesn't know which CPU is big and
which is little, unless you specify this in some way via the DT. It can
be the cpu nodes order or some other means.
--
Catalin
next prev parent reply other threads:[~2013-03-27 17:41 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-22 12:25 [RFC PATCH v3 0/6] sched: packing small tasks Vincent Guittot
2013-03-22 12:25 ` [RFC PATCH v3 1/6] Revert "sched: Introduce temporary FAIR_GROUP_SCHED dependency for load-tracking" Vincent Guittot
2013-03-22 12:25 ` [RFC PATCH v3 2/6] sched: add a new SD_SHARE_POWERDOMAIN flag for sched_domain Vincent Guittot
2013-03-22 12:25 ` [RFC PATCH v3 3/6] sched: pack small tasks Vincent Guittot
2013-03-26 12:26 ` Peter Zijlstra
2013-03-27 10:21 ` Preeti U Murthy
2013-03-27 11:00 ` Vincent Guittot
2013-04-26 10:30 ` Peter Zijlstra
2013-04-26 11:34 ` Vincent Guittot
2013-04-26 10:18 ` Peter Zijlstra
2013-04-26 10:32 ` Preeti U Murthy
2013-03-26 12:37 ` Peter Zijlstra
2013-03-26 13:00 ` Vincent Guittot
2013-03-27 4:33 ` Preeti U Murthy
2013-03-27 4:48 ` Alex Shi
2013-03-27 8:51 ` Peter Zijlstra
2013-03-26 12:46 ` Peter Zijlstra
2013-03-26 13:53 ` Vincent Guittot
2013-03-26 15:29 ` Arjan van de Ven
2013-03-27 8:46 ` Peter Zijlstra
2013-03-27 8:54 ` Vincent Guittot
2013-03-27 9:00 ` Peter Zijlstra
[not found] ` <20130327111855.GI801@MacBook-Pro.local>
[not found] ` <1364393634.5053.71.camel@laptop>
[not found] ` <20130327163642.GA1136@localhost.cambridge.arm.com>
2013-03-27 17:18 ` Nicolas Pitre
2013-03-27 17:37 ` Catalin Marinas [this message]
2013-03-27 15:37 ` Nicolas Pitre
2013-03-22 12:25 ` [RFC PATCH v3 4/6] sched: secure access to other CPU statistics Vincent Guittot
2013-03-26 12:50 ` Peter Zijlstra
2013-03-26 13:06 ` Vincent Guittot
2013-03-22 12:25 ` [RFC PATCH v3 5/6] sched: pack the idle load balance Vincent Guittot
2013-03-26 12:52 ` Peter Zijlstra
2013-03-26 14:03 ` Vincent Guittot
2013-03-26 14:42 ` Peter Zijlstra
2013-03-26 15:55 ` Vincent Guittot
2013-03-27 4:56 ` Alex Shi
2013-03-27 8:05 ` Vincent Guittot
2013-03-27 8:47 ` Alex Shi
2013-03-27 10:30 ` Vincent Guittot
2013-03-27 13:32 ` Alex Shi
2013-03-27 8:49 ` Peter Zijlstra
2013-04-05 11:08 ` Vincent Guittot
2013-04-22 5:45 ` Preeti U Murthy
[not found] ` <CAKfTPtCCCifC=c+xjjnAH_HSqkR80PiQoddQKXPHuZwZawbvcA@mail.gmail.com>
2013-04-23 2:23 ` Alex Shi
2013-04-23 4:57 ` Preeti U Murthy
2013-04-23 15:30 ` Arjan van de Ven
2013-04-26 10:54 ` Peter Zijlstra
2013-04-23 4:36 ` Preeti U Murthy
2013-03-22 12:25 ` [RFC PATCH v3 6/6] ARM: sched: clear SD_SHARE_POWERDOMAIN Vincent Guittot
2013-03-23 11:55 ` [RFC PATCH v3 0/6] sched: packing small tasks Preeti U Murthy
2013-03-25 9:58 ` Vincent Guittot
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