[PULL 17/17] cpus-common: stop using mb_set/mb_read

Paolo Bonzini posted 17 patches 2 years, 9 months ago
Maintainers: Richard Henderson <richard.henderson@linaro.org>, Paolo Bonzini <pbonzini@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, Cornelia Huck <cohuck@redhat.com>, Eric Blake <eblake@redhat.com>, Markus Armbruster <armbru@redhat.com>, Alessandro Di Federico <ale@rev.ng>, Anton Johansson <anjo@rev.ng>, Marcelo Tosatti <mtosatti@redhat.com>, Thomas Huth <thuth@redhat.com>, Laurent Vivier <lvivier@redhat.com>, Stefan Hajnoczi <stefanha@redhat.com>, Fam Zheng <fam@euphon.net>
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[PULL 17/17] cpus-common: stop using mb_set/mb_read
Posted by Paolo Bonzini 2 years, 9 months ago
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>
---
 cpus-common.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/cpus-common.c b/cpus-common.c
index b0047e456f93..a53716deb437 100644
--- 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);
-- 
2.40.0