CA-45967-handle_timer_interrupt_before_others

diff -r 5bfb3e5a2ac9 drivers/xen/core/evtchn.c
--- a/drivers/xen/core/evtchn.c	Thu Sep 30 11:33:23 2010 +0100
+++ b/drivers/xen/core/evtchn.c	Thu Sep 30 11:43:25 2010 +0100
@@ -360,6 +360,22 @@
 #else
 		barrier();
 #endif
+
+		/*
+		 * Handle timer interrupts before all others, so that all
+		 * hardirq handlers see an up-to-date system time even if we
+		 * have just woken from a long idle period.
+		 */
+		irq = percpu_read(virq_to_irq[VIRQ_TIMER]);
+		if (irq != -1) {
+		  port = evtchn_from_irq(irq);
+		  l1i = port / BITS_PER_LONG;
+		  l2i = port % BITS_PER_LONG;
+		  if (VALID_EVTCHN(port) &&
+		      (active_evtchns(l1i) & (1ul << l2i)))
+		    (void)handle_irq(irq, regs);
+		}
+
 		l1 = vcpu_info_xchg(evtchn_pending_sel, 0);
 
 		start_l1i = l1i = percpu_read(current_l1i);