diff mbox series

[2/5] evtchn: don't pointlessly use get_domain()

Message ID 1f9448ac-7889-3cfb-e136-d8c37f63279c@suse.com (mailing list archive)
State New, archived
Headers show
Series domain referencing adjustments | expand

Commit Message

Jan Beulich Jan. 5, 2021, 1:24 p.m. UTC 
For short-lived references rcu_lock_domain() is the better (slightly
cheaper) alternative.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
diff mbox series

Patch

--- a/xen/common/event_channel.c
+++ b/xen/common/event_channel.c
@@ -642,7 +642,7 @@  int evtchn_close(struct domain *d1, int
              */
             write_unlock(&chn1->lock);
             write_unlock(&chn2->lock);
-            put_domain(d2);
+            rcu_unlock_domain(d2);
             chn2 = NULL;
         }
 
@@ -677,7 +677,7 @@  int evtchn_close(struct domain *d1, int
              */
             write_unlock(&chn1->lock);
             write_unlock(&chn2->lock);
-            put_domain(d2);
+            rcu_unlock_domain(d2);
             chn2 = NULL;
         }
 
@@ -725,9 +725,8 @@  int evtchn_close(struct domain *d1, int
 
         if ( !chn2 )
         {
-            /* If we unlock chn1 then we could lose d2. Must get a reference. */
-            if ( unlikely(!get_domain(d2)) )
-                BUG();
+            /* If we unlock chn1 then we could lose d2. */
+            rcu_lock_domain(d2);
 
             chn2 = _evtchn_from_port(d2, chn1->u.interdomain.remote_port);
             BUG_ON(!chn2);
@@ -778,7 +777,7 @@  int evtchn_close(struct domain *d1, int
          */
         write_unlock(&chn1->lock);
         write_unlock(&chn2->lock);
-        put_domain(d2);
+        rcu_unlock_domain(d2);
     }
 
     write_unlock(&d1->event_lock);