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From: Scott Wood <scottwood@freescale.com>
To: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org, Greg Kurz <gkurz@linux.vnet.ibm.com>
Subject: Re: [PATCH 2 1/4] powerpc: drop the ability to tweak SMT mode at boot time
Date: Tue, 9 Dec 2014 15:04:44 -0600	[thread overview]
Message-ID: <1418159084.5581.32.camel@freescale.com> (raw)
In-Reply-To: <1418098262.527.1.camel@concordia>

On Tue, 2014-12-09 at 15:11 +1100, Michael Ellerman wrote:
> On Fri, 2014-12-05 at 12:52 -0600, Scott Wood wrote:
> > On Fri, 2014-12-05 at 16:14 +0100, Greg Kurz wrote:
> > > The smt-enabled kernel parameter basically leaves unwanted cpus executing
> > > in firmware or wherever they happen to be. The very same applies to the
> > > ibm,smt-enabled DT property which is no more used by anything known. These
> > > are hacks that shoudn't be used in a production environment.
> > > 
> > > Quoting mpe, "there are better ways for firmware to disable SMT".
> > 
> > Those "better ways" don't apply to Freescale chips, where the OS enables
> > (or not) SMT without any interaction with firmware.
> 
> But how does it know there even are SMT threads? From the device tree? So
> just don't present the threads in the device tree?

The device tree is for hardware description, not configuration...

-Scott

  parent reply	other threads:[~2014-12-09 21:04 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-12-05 15:13 [PATCH 2 0/4] powerpc: don't mess with SMT at boot time Greg Kurz
2014-12-05 15:14 ` [PATCH 2 1/4] powerpc: drop the ability to tweak SMT mode " Greg Kurz
2014-12-05 18:52   ` Scott Wood
2014-12-08  8:23     ` Greg Kurz
2014-12-08 22:39       ` Scott Wood
2014-12-09  4:11     ` Michael Ellerman
2014-12-09  8:53       ` Greg Kurz
2014-12-09 21:04       ` Scott Wood [this message]
2014-12-09 23:56         ` Michael Ellerman
2014-12-10  0:14           ` Scott Wood
2014-12-10  2:14             ` Michael Ellerman
2014-12-10 23:50               ` Scott Wood
2014-12-12  5:19                 ` Michael Ellerman
2014-12-05 15:14 ` [PATCH 2 2/4] powerpc: drop smt_enabled_at_boot Greg Kurz
2014-12-05 15:15 ` [PATCH 2 3/4] powerpc: drop smp_generic_cpu_bootable() Greg Kurz
2014-12-05 15:34   ` Greg Kurz
2014-12-05 15:15 ` [PATCH 2 4/4] powerpc: drop the cpu_bootable hook Greg Kurz
2014-12-05 15:42   ` [PATCH] " Greg Kurz
2014-12-12  5:22 ` [PATCH 2 0/4] powerpc: don't mess with SMT at boot time Michael Ellerman

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