sched: add .init_pdata hook to the scheduler interface

with the purpose of decoupling the allocation phase and
the initialization one, for per-pCPU data of the schedulers.

This makes it possible to perform the initialization later
in the pCPU bringup/assignement process, when more information
(for instance, the host CPU topology) are available. This,
for now, is important only for Credit2, but it can well be
useful to other schedulers.

Signed-off-by: Dario Faggioli <dario.faggioli@citrix.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: George Dunlap <george.dunlap@citrix.com>

diff --git a/xen/common/schedule.c b/xen/common/schedule.c
index e57b659f655bf01731d88c2684c33586e2ef9975..0627eb5cdcfc7d0bf80e3dff9e4c9ddf2e840302 100644 (file)
--- a/xen/common/schedule.c
+++ b/xen/common/schedule.c
@@ -1517,10 +1517,15 @@ static int cpu_schedule_callback(
     struct notifier_block *nfb, unsigned long action, void *hcpu)
 {
     unsigned int cpu = (unsigned long)hcpu;
+    struct scheduler *sched = per_cpu(scheduler, cpu);
+    struct schedule_data *sd = &per_cpu(schedule_data, cpu);
     int rc = 0;
 
     switch ( action )
     {
+    case CPU_STARTING:
+        SCHED_OP(sched, init_pdata, sd->sched_priv, cpu);
+        break;
     case CPU_UP_PREPARE:
         rc = cpu_schedule_up(cpu);
         break;
@@ -1597,6 +1602,7 @@ void __init scheduler_init(void)
     if ( ops.alloc_pdata &&
          !(this_cpu(schedule_data).sched_priv = ops.alloc_pdata(&ops, 0)) )
         BUG();
+    SCHED_OP(&ops, init_pdata, this_cpu(schedule_data).sched_priv, 0);
 }
 
 /*
@@ -1640,6 +1646,7 @@ int schedule_cpu_switch(unsigned int cpu, struct cpupool *c)
     ppriv = SCHED_OP(new_ops, alloc_pdata, cpu);
     if ( ppriv == NULL )
         return -ENOMEM;
+    SCHED_OP(new_ops, init_pdata, ppriv, cpu);
     vpriv = SCHED_OP(new_ops, alloc_vdata, idle, idle->domain->sched_priv);
     if ( vpriv == NULL )
     {

diff --git a/xen/include/xen/sched-if.h b/xen/include/xen/sched-if.h
index 825f1adb08d2a9462d794be337dda25bb49b257d..70c08c6b734131e8e660d2c20391a1ec83667182 100644 (file)
--- a/xen/include/xen/sched-if.h
+++ b/xen/include/xen/sched-if.h
@@ -133,6 +133,7 @@ struct scheduler {
                                     void *);
     void         (*free_pdata)     (const struct scheduler *, void *, int);
     void *       (*alloc_pdata)    (const struct scheduler *, int);
+    void         (*init_pdata)     (const struct scheduler *, void *, int);
     void         (*free_domdata)   (const struct scheduler *, void *);
     void *       (*alloc_domdata)  (const struct scheduler *, struct domain *);