From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Colin Cross <ccross@android.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>,
linux-arm-kernel@lists.infradead.org,
linux-samsung-soc@vger.kernel.org, ben-linux@fluff.org,
Changhwan Youn <chaos.youn@samsung.com>,
Tony Lindgren <tony@atomide.com>,
Erik Gilling <konkers@android.com>,
Olof Johansson <olof@lixom.net>
Subject: Re: [PATCH 2/2] ARM: S5PV310: Update CPU hotplug implementation
Date: Thu, 30 Sep 2010 22:21:01 +0100 [thread overview]
Message-ID: <20100930212101.GC11660@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <AANLkTinaGsnZg-nTGvXS4xw-_8e8+pLpL4hYN-HMNYfh@mail.gmail.com>
On Thu, Sep 30, 2010 at 10:02:37AM -0700, Colin Cross wrote:
> On Wed, Sep 29, 2010 at 4:58 AM, Kukjin Kim <kgene.kim@samsung.com> wrote:
> > Kukjin Kim wrote:
> >>
> >> From: Changhwan Youn <chaos.youn@samsung.com>
> >>
> >> This patch updates CPU hotplug implementation to reduce CPU power
> >> consumption
> >> and will turn off the CPU power when CPU1 is unplugged while previous CPU
> >> hotplug
> >> used CPU idle.
> >> This patch removes init memory freeing code to use CPU boot code when CPU1
> > is
> >> plugged-in again and adds vfp_enable() call to allow to access CP10 and
> > CP11.
> >>
> >> Signed-off-by: Changhwan Youn <chaos.youn@samsung.com>
> >> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
> >> Cc: Russell King <rmk@arm.linux.org.uk>
> > Cc: Tony Lindgren <tony@atomide.com>
> > Cc: Colin Cross <ccross@android.com>
> > Cc: Erik Gilling <konkers@android.com>
> > Cc: Olof Johansson <olof@lixom.net>
> >
>
> snip
>
> >> +#ifndef CONFIG_HOTPLUG_CPU
> >> if (!machine_is_integrator() && !machine_is_cintegrator())
> >> totalram_pages +=
> > free_area(__phys_to_pfn(__pa(__init_begin)),
> >> __phys_to_pfn(__pa(__init_end)),
> >> "init");
> >> +#endif
> >> }
> >>
> >> #ifdef CONFIG_BLK_DEV_INITRD
>
> I don't think this is necessary. Any symbol that is necessary for CPU
> hotplug should be marked with __cpuinit instead of __init. The linker
> script will put __cpuinit symbols outside the __init_begin -
> __init_end section if CONFIG_HOTPLUG_CPU is enabled.
That's the theory, but not everything required for a complete restart of
a secondary CPU (iow, if it's powered off) is in the right section yet.
I'll have patches hopefully tomorrow to address this.
prev parent reply other threads:[~2010-09-30 21:21 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-09-17 5:13 [PATCH 0/2] ARM: S5PV310: Update S5PV310 CPU hotplug implementation Kukjin Kim
2010-09-17 5:13 ` [PATCH 1/2] ARM: S5PV310: Add PMU for S5PV310 hotplug Kukjin Kim
2010-09-17 7:58 ` Kukjin Kim
2010-09-17 5:13 ` [PATCH 2/2] ARM: S5PV310: Update CPU hotplug implementation Kukjin Kim
2010-09-29 11:58 ` Kukjin Kim
2010-09-30 17:02 ` Colin Cross
2010-09-30 21:21 ` Russell King - ARM Linux [this message]
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