# HG changeset patch
# User kaf24@xxxxxxxxxxxxxxxxxxxx
# Node ID c1840ac1f05d32fb6c4b39253b53c301167c2e75
# Parent 0c5980d0bf20f3806a3aaaeb0e0bf87ac1671f38
Introduce a locking protocol for acquiring the 'scheduler
lock' on a particular VCPU. Since this requires acquiring
the approrpiate per-CPU lock, we must re-check the VCPU's
current CPU binding after the lock is acquired.
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
diff -r 0c5980d0bf20 -r c1840ac1f05d xen/common/sched_bvt.c
--- a/xen/common/sched_bvt.c Fri Jan 13 15:27:45 2006
+++ b/xen/common/sched_bvt.c Fri Jan 13 15:44:04 2006
@@ -98,9 +98,9 @@
static void warp_timer_fn(void *data)
{
struct bvt_dom_info *inf = data;
- unsigned int cpu = inf->domain->vcpu[0]->processor;
-
- spin_lock_irq(&schedule_data[cpu].schedule_lock);
+ struct vcpu *v = inf->domain->vcpu[0];
+
+ vcpu_schedule_lock_irq(v);
inf->warp = 0;
@@ -108,28 +108,28 @@
if ( inf->warpu == 0 )
{
inf->warpback = 0;
- cpu_raise_softirq(cpu, SCHEDULE_SOFTIRQ);
+ cpu_raise_softirq(v->processor, SCHEDULE_SOFTIRQ);
}
set_timer(&inf->unwarp_timer, NOW() + inf->warpu);
- spin_unlock_irq(&schedule_data[cpu].schedule_lock);
+ vcpu_schedule_unlock_irq(v);
}
static void unwarp_timer_fn(void *data)
{
struct bvt_dom_info *inf = data;
- unsigned int cpu = inf->domain->vcpu[0]->processor;
-
- spin_lock_irq(&schedule_data[cpu].schedule_lock);
+ struct vcpu *v = inf->domain->vcpu[0];
+
+ vcpu_schedule_lock_irq(v);
if ( inf->warpback )
{
inf->warp = 1;
- cpu_raise_softirq(cpu, SCHEDULE_SOFTIRQ);
+ cpu_raise_softirq(v->processor, SCHEDULE_SOFTIRQ);
}
- spin_unlock_irq(&schedule_data[cpu].schedule_lock);
+ vcpu_schedule_unlock_irq(v);
}
static inline u32 calc_avt(struct vcpu *d, s_time_t now)
diff -r 0c5980d0bf20 -r c1840ac1f05d xen/common/schedule.c
--- a/xen/common/schedule.c Fri Jan 13 15:27:45 2006
+++ b/xen/common/schedule.c Fri Jan 13 15:44:04 2006
@@ -165,10 +165,10 @@
{
unsigned long flags;
- spin_lock_irqsave(&schedule_data[v->processor].schedule_lock, flags);
+ vcpu_schedule_lock_irqsave(v, flags);
if ( likely(!vcpu_runnable(v)) )
SCHED_OP(sleep, v);
- spin_unlock_irqrestore(&schedule_data[v->processor].schedule_lock, flags);
+ vcpu_schedule_unlock_irqrestore(v, flags);
TRACE_2D(TRC_SCHED_SLEEP, v->domain->domain_id, v->vcpu_id);
}
@@ -187,13 +187,13 @@
{
unsigned long flags;
- spin_lock_irqsave(&schedule_data[v->processor].schedule_lock, flags);
+ vcpu_schedule_lock_irqsave(v, flags);
if ( likely(vcpu_runnable(v)) )
{
SCHED_OP(wake, v);
v->wokenup = NOW();
}
- spin_unlock_irqrestore(&schedule_data[v->processor].schedule_lock, flags);
+ vcpu_schedule_unlock_irqrestore(v, flags);
TRACE_2D(TRC_SCHED_WAKE, v->domain->domain_id, v->vcpu_id);
}
@@ -324,7 +324,7 @@
for_each_vcpu ( d, v )
{
if ( v == current )
- spin_lock_irq(&schedule_data[smp_processor_id()].schedule_lock);
+ vcpu_schedule_lock_irq(v);
else
vcpu_pause(v);
}
@@ -336,7 +336,7 @@
for_each_vcpu ( d, v )
{
if ( v == current )
- spin_unlock_irq(&schedule_data[smp_processor_id()].schedule_lock);
+ vcpu_schedule_unlock_irq(v);
else
vcpu_unpause(v);
}
diff -r 0c5980d0bf20 -r c1840ac1f05d xen/include/xen/sched-if.h
--- a/xen/include/xen/sched-if.h Fri Jan 13 15:27:45 2006
+++ b/xen/include/xen/sched-if.h Fri Jan 13 15:44:04 2006
@@ -16,16 +16,47 @@
struct vcpu *curr; /* current task */
struct vcpu *idle; /* idle task for this cpu */
void *sched_priv;
- struct timer s_timer; /* scheduling timer */
+ struct timer s_timer; /* scheduling timer */
unsigned long tick; /* current periodic 'tick' */
#ifdef BUCKETS
u32 hist[BUCKETS]; /* for scheduler latency histogram */
#endif
} __cacheline_aligned;
+extern struct schedule_data schedule_data[];
+
+static inline void vcpu_schedule_lock(struct vcpu *v)
+{
+ unsigned int cpu;
+
+ for ( ; ; )
+ {
+ cpu = v->processor;
+ spin_lock(&schedule_data[cpu].schedule_lock);
+ if ( likely(v->processor == cpu) )
+ break;
+ spin_unlock(&schedule_data[cpu].schedule_lock);
+ }
+}
+
+#define vcpu_schedule_lock_irq(v) \
+ do { local_irq_disable(); vcpu_schedule_lock(v); } while ( 0 )
+#define vcpu_schedule_lock_irqsave(v, flags) \
+ do { local_irq_save(flags); vcpu_schedule_lock(v); } while ( 0 )
+
+static inline void vcpu_schedule_unlock(struct vcpu *v)
+{
+ spin_unlock(&schedule_data[v->processor].schedule_lock);
+}
+
+#define vcpu_schedule_unlock_irq(v) \
+ do { vcpu_schedule_unlock(v); local_irq_enable(); } while ( 0 )
+#define vcpu_schedule_unlock_irqrestore(v, flags) \
+ do { vcpu_schedule_unlock(v); local_irq_restore(flags); } while ( 0 )
+
struct task_slice {
struct vcpu *task;
- s_time_t time;
+ s_time_t time;
};
struct scheduler {
@@ -48,6 +79,4 @@
void (*dump_cpu_state) (int);
};
-extern struct schedule_data schedule_data[];
-
#endif /* __XEN_SCHED_IF_H__ */
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