From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: do not mark CPU 0 as hotpluggable
Date: Thu, 21 Jul 2011 08:45:11 +0100 [thread overview]
Message-ID: <20110721074511.GK26574@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <1311204745-6276-1-git-send-email-mturquette@ti.com>
On Wed, Jul 20, 2011 at 04:32:25PM -0700, Mike Turquette wrote:
> A quick poll of the ARM platforms that implement CPU Hotplug support
> shows that every platform treats CPU 0 as a special case that cannot be
> hotplugged. In fact every platform has identical code for
> platform_cpu_die which returns -EPERM in the case of CPU 0.
Are you sure that's just not because everyone copied what Realview has
been doing (highly likely)?
I suspect that there's no reason that CPU0 can't be taken down, especially
on those platforms which don't take the CPU fully offline but just put it
into a WFI loop.
Those which restart the CPUs through the boot loader probably detect CPU0
as the boot CPU, so they probably can't take CPU0 down.
next prev parent reply other threads:[~2011-07-21 7:45 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-20 23:32 [PATCH] ARM: do not mark CPU 0 as hotpluggable Mike Turquette
2011-07-21 3:02 ` Rob Herring
2011-07-21 5:33 ` Santosh Shilimkar
2011-07-21 13:30 ` Russell King - ARM Linux
2011-07-22 4:56 ` Santosh Shilimkar
2011-07-22 12:45 ` Woodruff, Richard
2011-07-22 12:53 ` Santosh Shilimkar
2011-08-12 1:31 ` Turquette, Mike
2011-07-21 7:45 ` Russell King - ARM Linux [this message]
2011-07-21 21:22 ` Woodruff, Richard
2011-07-21 22:18 ` Turquette, Mike
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