cpus-common: stop using mb_set/mb_read

Use a store-release at the end of the work item, and a load-acquire when
waiting for the item to be completed.  This is the standard message passing
pattern and is both enough and clearer than mb_read/mb_set.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/cpus-common.c b/cpus-common.c
index b0047e456f93472a9c2e08190cdc457391d79ec7..a53716deb43731ad8cf85f645b8b15e355dbcabc 100644 (file)
--- a/cpus-common.c
+++ b/cpus-common.c
@@ -157,7 +157,7 @@ void do_run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data data,
     wi.exclusive = false;
 
     queue_work_on_cpu(cpu, &wi);
-    while (!qatomic_mb_read(&wi.done)) {
+    while (!qatomic_load_acquire(&wi.done)) {
         CPUState *self_cpu = current_cpu;
 
         qemu_cond_wait(&qemu_work_cond, mutex);
@@ -363,7 +363,7 @@ void process_queued_cpu_work(CPUState *cpu)
         if (wi->free) {
             g_free(wi);
         } else {
-            qatomic_mb_set(&wi->done, true);
+            qatomic_store_release(&wi->done, true);
         }
     }
     qemu_mutex_unlock(&cpu->work_mutex);