[PATCH 1 of 2] scheduler: Add a per-scheduler yield callback

[George Dunlap <george.dunlap@eu.citrix.com>]

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>

diff -r 6f07d9ac1e7c -r 1c9288cd2af3 xen/common/schedule.c
--- a/xen/common/schedule.c	Thu Aug 05 14:41:14 2010 +0100
+++ b/xen/common/schedule.c	Fri Aug 06 15:41:56 2010 +0100
@@ -641,6 +641,12 @@
 /* Voluntarily yield the processor for this allocation. */
 static long do_yield(void)
 {
+    struct vcpu * v=current;
+
+    vcpu_schedule_lock_irq(v);
+    SCHED_OP(VCPU2OP(v), yield, v);
+    vcpu_schedule_unlock_irq(v);
+
     TRACE_2D(TRC_SCHED_YIELD, current->domain->domain_id, current->vcpu_id);
     raise_softirq(SCHEDULE_SOFTIRQ);
     return 0;
diff -r 6f07d9ac1e7c -r 1c9288cd2af3 xen/include/xen/sched-if.h
--- a/xen/include/xen/sched-if.h	Thu Aug 05 14:41:14 2010 +0100
+++ b/xen/include/xen/sched-if.h	Fri Aug 06 15:41:56 2010 +0100
@@ -107,6 +107,7 @@
 
     void         (*sleep)          (const struct scheduler *, struct vcpu *);
     void         (*wake)           (const struct scheduler *, struct vcpu *);
+    void         (*yield)           (const struct scheduler *, struct vcpu *);
     void         (*context_saved)  (const struct scheduler *, struct vcpu *);
 
     struct task_slice (*do_schedule) (const struct scheduler *, s_time_t,