[PATCH 5 of 5] xen: don't worry about preempt during xen_irq_enable()

From: Jeremy Fitzhardinge
Date: Fri May 23 2008 - 09:14:15 EST

When enabling interrupts, we don't need to worry about preemption,
because we either enter with interrupts disabled - so no preemption -
or the caller is confused and is re-enabling interrupts on some
indeterminate processor.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
arch/x86/xen/enlighten.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -235,13 +235,13 @@
struct vcpu_info *vcpu;

- /* There's a one instruction preempt window here. We need to
- make sure we're don't switch CPUs between getting the vcpu
- pointer and updating the mask. */
- preempt_disable();
+ /* We don't need to worry about being preempted here, since
+ either a) interrupts are disabled, so no preemption, or b)
+ the caller is confused and is trying to re-enable interrupts
+ on an indeterminate processor. */
vcpu = x86_read_percpu(xen_vcpu);
vcpu->evtchn_upcall_mask = 0;
- preempt_enable_no_resched();

/* Doesn't matter if we get preempted here, because any
pending event will get dealt with anyway. */

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