[Xen-devel] [PATCH RFC 46/49] xen/sched: add a scheduler_percpu_init() function

[Juergen Gross <jgross@xxxxxxxx>]

For support of core scheduling the scheduler cpu callback for
CPU_STARTING has to be moved into a dedicated function called by
start_secondary() as it needs to run before spin_debug_enable() then
due to potentially calling xfree().

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
 xen/arch/arm/smpboot.c  |  2 ++
 xen/arch/x86/smpboot.c  |  2 ++
 xen/common/schedule.c   | 19 ++++++++++++-------
 xen/include/xen/sched.h |  1 +
 4 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c
index 0728a9b505..3ae32449d7 100644
--- a/xen/arch/arm/smpboot.c
+++ b/xen/arch/arm/smpboot.c
@@ -350,6 +350,8 @@ void start_secondary(unsigned long boot_phys_offset,
 
     setup_cpu_sibling_map(cpuid);
 
+    scheduler_percpu_init(cpu);
+
     /* Run local notifiers */
     notify_cpu_starting(cpuid);
     /*
diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c
index b7a0a4a419..1c4f628b97 100644
--- a/xen/arch/x86/smpboot.c
+++ b/xen/arch/x86/smpboot.c
@@ -383,6 +383,8 @@ void start_secondary(void *unused)
 
     set_cpu_sibling_map(cpu);
 
+    scheduler_percpu_init(cpu);
+
     init_percpu_time();
 
     setup_secondary_APIC_clock();
diff --git a/xen/common/schedule.c b/xen/common/schedule.c
index a2140b3d7c..f43d00b59f 100644
--- a/xen/common/schedule.c
+++ b/xen/common/schedule.c
@@ -2029,6 +2029,15 @@ static void cpu_schedule_down(unsigned int cpu)
     per_cpu(sched_res, cpu) = NULL;
 }
 
+void scheduler_percpu_init(unsigned int cpu)
+{
+    struct scheduler *sched = per_cpu(scheduler, cpu);
+    struct sched_resource *sd = per_cpu(sched_res, cpu);
+
+    if ( system_state != SYS_STATE_resume )
+        SCHED_OP(sched, init_pdata, sd->sched_priv, cpu);
+}
+
 static int cpu_schedule_callback(
     struct notifier_block *nfb, unsigned long action, void *hcpu)
 {
@@ -2047,8 +2056,8 @@ static int cpu_schedule_callback(
      * data can avoid implementing alloc_pdata. init_pdata may, however, be
      * necessary/useful in this case too (e.g., it can contain the "register
      * the pCPU to the scheduler" part). alloc_pdata (if present) is called
-     * during CPU_UP_PREPARE. init_pdata (if present) is called during
-     * CPU_STARTING.
+     * during CPU_UP_PREPARE. init_pdata (if present) is called before
+     * CPU_STARTING in scheduler_percpu_init().
      *
      * On the other hand, at teardown, we need to reverse what has been done
      * during initialization, and then free the per-pCPU specific data. This
@@ -2071,10 +2080,6 @@ static int cpu_schedule_callback(
      */
     switch ( action )
     {
-    case CPU_STARTING:
-        if ( system_state != SYS_STATE_resume )
-            SCHED_OP(sched, init_pdata, sd->sched_priv, cpu);
-        break;
     case CPU_UP_PREPARE:
         if ( system_state != SYS_STATE_resume )
             rc = cpu_schedule_up(cpu);
@@ -2171,7 +2176,7 @@ void __init scheduler_init(void)
     this_cpu(sched_res)->curr = idle_vcpu[0]->sched_item;
     this_cpu(sched_res)->sched_priv = SCHED_OP(&ops, alloc_pdata, 0);
     BUG_ON(IS_ERR(this_cpu(sched_res)->sched_priv));
-    SCHED_OP(&ops, init_pdata, this_cpu(sched_res)->sched_priv, 0);
+    scheduler_percpu_init(0);
 }
 
 /*
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 314a453a60..51b8b6a44f 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -632,6 +632,7 @@ void __domain_crash(struct domain *d);
 void noreturn asm_domain_crash_synchronous(unsigned long addr);
 
 void scheduler_init(void);
+void scheduler_percpu_init(unsigned int cpu);
 int  sched_init_vcpu(struct vcpu *v);
 void sched_destroy_vcpu(struct vcpu *v);
 int  sched_init_domain(struct domain *d, int poolid);
-- 
2.16.4


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