[PATCH v17 02/13] arm64: Add cpus_are_stuck_in_kernel

Hi Geoff,

On 03/06/16 19:13, Geoff Levand wrote:

From: James Morse <james.morse@arm.com>

kernel/smp.c has a fancy counter that keeps track of the number of CPUs
it marked as not-present and left in cpu_park_loop(). If there are any
CPUs spinning in here, kexec will release them once the memory is re-used
by the new kernel.

We can't return an error once we reach machine_kexec(), so as a sanity check
we forbid kexec images to be loaded if there are already cpus stuck in the
kernel, or we have multiple cpus and no way of disabling them.

Signed-off-by: James Morse <james.morse@arm.com>
[Split off from a larger patch]
Signed-off-by: Geoff Levand <geoff@infradead.org>

Post-split, the second paragraph of the commit message is out of place, and
doesn't describe what the patch does. Can I suggest replacing it with:

Provide a function to expose whether this counter is non-zero, so we can use >

this when loading a new kexec image, and when calling machine_kexec().


Thanks,

James