@@ -171,8 +171,7 @@ static inline void exclusive_idle(void)
}
/* Start an exclusive operation.
- Must only be called from outside cpu_exec, takes
- qemu_cpu_list_lock. */
+ Must only be called from outside cpu_exec. */
void start_exclusive(void)
{
CPUState *other_cpu;
@@ -191,11 +190,17 @@ void start_exclusive(void)
while (pending_cpus > 1) {
qemu_cond_wait(&exclusive_cond, &qemu_cpu_list_lock);
}
+
+ /* Can release mutex, no one will enter another exclusive
+ * section until end_exclusive resets pending_cpus to 0.
+ */
+ qemu_mutex_unlock(&qemu_cpu_list_lock);
}
-/* Finish an exclusive operation. Releases qemu_cpu_list_lock. */
+/* Finish an exclusive operation. */
void end_exclusive(void)
{
+ qemu_mutex_lock(&qemu_cpu_list_lock);
pending_cpus = 0;
qemu_cond_broadcast(&exclusive_resume);
qemu_mutex_unlock(&qemu_cpu_list_lock);
@@ -98,9 +98,11 @@ byte has_waiter[N_CPUS];
do \
:: pending_cpus > 1 -> COND_WAIT(exclusive_cond, mutex); \
:: else -> break; \
- od
+ od; \
+ MUTEX_UNLOCK(mutex);
#define end_exclusive() \
+ MUTEX_LOCK(mutex); \
pending_cpus = 0; \
COND_BROADCAST(exclusive_resume); \
MUTEX_UNLOCK(mutex);
@@ -846,9 +846,6 @@ void cpu_exec_end(CPUState *cpu);
* cpu_exec are exited immediately. CPUs that call cpu_exec_start
* during the exclusive section go to sleep until this CPU calls
* end_exclusive.
- *
- * Returns with the CPU list lock taken (which nests outside all
- * other locks except the BQL).
*/
void start_exclusive(void);
@@ -856,7 +853,6 @@ void start_exclusive(void);
* end_exclusive:
*
* Concludes an exclusive execution section started by start_exclusive.
- * Releases the CPU list lock.
*/
void end_exclusive(void);