From: Sage Weil <sage@redhat.com>
Date: Wed, 7 Sep 2016 20:46:57 +0000 (-0400)
Subject: os/bluestore: do not waste memory on cached encoded blobs
X-Git-Tag: v11.0.1~298^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=refs%2Fpull%2F11011%2Fhead;p=ceph.git

os/bluestore: do not waste memory on cached encoded blobs

Signed-off-by: Sage Weil <sage@redhat.com>
---

diff --git a/src/os/bluestore/BlueStore.h b/src/os/bluestore/BlueStore.h
index 120294bcc465..e50f899b8198 100644
--- a/src/os/bluestore/BlueStore.h
+++ b/src/os/bluestore/BlueStore.h
@@ -473,6 +473,9 @@ public:
 
     void encode(bufferlist& bl) const {
       if (dirty) {
+	// manage blob_bl memory carefully
+	blob_bl.clear();
+	blob_bl.reserve(blob.estimate_encoded_size());
 	::encode(blob, blob_bl);
 	dirty = false;
       } else {
diff --git a/src/os/bluestore/bluestore_types.h b/src/os/bluestore/bluestore_types.h
index 5da333d17a78..f0203c930b98 100644
--- a/src/os/bluestore/bluestore_types.h
+++ b/src/os/bluestore/bluestore_types.h
@@ -303,6 +303,11 @@ struct bluestore_blob_t {
 
   bluestore_blob_t(uint32_t f = 0) : flags(f) {}
 
+  int estimate_encoded_size() const {
+    // conservative upper bound... fixme
+    return csum_data.length() + extents.size() * 16 + 48;
+  }
+
   void encode(bufferlist& bl) const;
   void decode(bufferlist::iterator& p);
   void dump(Formatter *f) const;