1 files changed, 12 insertions, 6 deletions

diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index 8ff37995d54e..d99cae8147d1 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -17,6 +17,7 @@
 #include <linux/slab.h>
 #include <linux/smp.h>
 #include <linux/irq_work.h>
+#include <linux/tick.h>
 
 #include <asm/paravirt.h>
 #include <asm/desc.h>
@@ -447,6 +448,13 @@ 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();
+        /*
+         * commit 4b0c0f294 (tick: Cleanup NOHZ per cpu data on cpu down)
+         * clears certain data that the cpu_idle loop (which called us
+         * and that we return from) expects. The only way to get that
+         * data back is to call:
+         */
+        tick_nohz_idle_enter();
 }
 
 #else /* !CONFIG_HOTPLUG_CPU */
@@ -576,24 +584,22 @@ void xen_send_IPI_mask_allbutself(const struct cpumask *mask,
 {
         unsigned cpu;
         unsigned int this_cpu = smp_processor_id();
+        int xen_vector = xen_map_vector(vector);
 
-        if (!(num_online_cpus() > 1))
+        if (!(num_online_cpus() > 1) || (xen_vector < 0))
                 return;
 
         for_each_cpu_and(cpu, mask, cpu_online_mask) {
                 if (this_cpu == cpu)
                         continue;
 
-                xen_smp_send_call_function_single_ipi(cpu);
+                xen_send_IPI_one(cpu, xen_vector);
         }
 }
 
 void xen_send_IPI_allbutself(int vector)
 {
-        int xen_vector = xen_map_vector(vector);
-
-        if (xen_vector >= 0)
-                xen_send_IPI_mask_allbutself(cpu_online_mask, xen_vector);
+        xen_send_IPI_mask_allbutself(cpu_online_mask, vector);
 }
 
 static irqreturn_t xen_call_function_interrupt(int irq, void *dev_id)