From: tangwenjun <tang.wenjun3@zte.com.cn>
Date: Mon, 20 Nov 2017 02:33:07 +0000 (+0800)
Subject: os/bluestore: reduce meaningless flush
X-Git-Tag: v13.0.2~838^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=af8a25cdcaf43eb045243c222cd97c399bc2e1f6;p=ceph.git

os/bluestore: reduce meaningless flush

no need to flush when there is no summitted aio

Signed-off-by: tangwenjun <tang.wenjun3@zte.com.cn>
---

diff --git a/src/os/bluestore/BlueStore.cc b/src/os/bluestore/BlueStore.cc
index 3c2c348b1c38..9401e69c6068 100644
--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -8550,8 +8550,13 @@ void BlueStore::_kv_sync_thread()
 	} else if (deferred_aggressive) {
 	  force_flush = true;
 	}
-      } else
-	force_flush = true;
+      } else {
+      	if (aios || !deferred_done.empty()) {
+	  force_flush = true;
+      	} else {
+	  dout(20) << __func__ << " skipping flush (no aios, no deferred_done)" << dendl;
+      	}
+      }
 
       if (force_flush) {
 	dout(20) << __func__ << " num_aios=" << aios