[PULL 07/19] migration/multifd: sync packet_num after all thread are done

From: Juan Quintela <quintela@redhat.com>
To: qemu-devel@nongnu.org
Cc: Laurent Vivier <lvivier@redhat.com>,
	Richard Henderson <rth@twiddle.net>,
	Paolo Bonzini <pbonzini@redhat.com>,
	kvm@vger.kernel.org,
	"Dr. David Alan Gilbert" <dgilbert@redhat.com>,
	Juan Quintela <quintela@redhat.com>,
	Thomas Huth <thuth@redhat.com>,
	Wei Yang <richardw.yang@linux.intel.com>,
	Peter Xu <peterx@redhat.com>
Subject: [PULL 07/19] migration/multifd: sync packet_num after all thread are done
Date: Fri, 12 Jul 2019 16:31:55 +0200	[thread overview]
Message-ID: <20190712143207.4214-8-quintela@redhat.com> (raw)
In-Reply-To: <20190712143207.4214-1-quintela@redhat.com>

From: Wei Yang <richardw.yang@linux.intel.com>

Notification from recv thread is not ordered, which means we may be
notified by one MultiFDRecvParams but adjust packet_num for another.

Move the adjustment after we are sure each recv thread are sync-ed.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Message-Id: <20190604023540.26532-1-richardw.yang@linux.intel.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 migration/ram.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index d3d72b6f4f..96c84f770a 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1291,15 +1291,15 @@ static void multifd_recv_sync_main(void)
 
         trace_multifd_recv_sync_main_wait(p->id);
         qemu_sem_wait(&multifd_recv_state->sem_sync);
+    }
+    for (i = 0; i < migrate_multifd_channels(); i++) {
+        MultiFDRecvParams *p = &multifd_recv_state->params[i];
+
         qemu_mutex_lock(&p->mutex);
         if (multifd_recv_state->packet_num < p->packet_num) {
             multifd_recv_state->packet_num = p->packet_num;
         }
         qemu_mutex_unlock(&p->mutex);
-    }
-    for (i = 0; i < migrate_multifd_channels(); i++) {
-        MultiFDRecvParams *p = &multifd_recv_state->params[i];
-
         trace_multifd_recv_sync_main_signal(p->id);
         qemu_sem_post(&p->sem_sync);
     }
-- 
2.21.0

