[PATCH 05/27] xen,cpu hotplug: Don't call cpu_bringup() in xen_play_dead()

From: Srivatsa S. Bhat
Date: Fri Jun 01 2012 - 05:12:18 EST


xen_play_dead calls cpu_bringup() which looks weird, because xen_play_dead()
is invoked in the cpu down path, whereas cpu_bringup() (as the name suggests)
is useful in the cpu bringup path.

Getting rid of xen_play_dead()'s dependency on cpu_bringup() helps in hooking
on to the generic SMP booting framework.

Also remove the extra call to preempt_enable() added by commit 41bd956
(xen/smp: Fix CPU online/offline bug triggering a BUG: scheduling while
atomic) because it becomes unnecessary after this change.

Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: x86@xxxxxxxxxx
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx
Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx>
---

arch/x86/xen/smp.c | 8 --------
1 files changed, 0 insertions(+), 8 deletions(-)

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 09a7199..602d6b7 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -417,14 +417,6 @@ static void __cpuinit xen_play_dead(void) /* used only with HOTPLUG_CPU */
{
play_dead_common();
HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
- cpu_bringup();
- /*
- * Balance out the preempt calls - as we are running in cpu_idle
- * loop which has been called at bootup from cpu_bringup_and_idle.
- * The cpucpu_bringup_and_idle called cpu_bringup which made a
- * preempt_disable() So this preempt_enable will balance it out.
- */
- preempt_enable();
}

#else /* !CONFIG_HOTPLUG_CPU */

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