From: Radoslaw Zarzynski <rzarzyns@redhat.com>
Date: Fri, 23 Mar 2018 21:13:13 +0000 (+0100)
Subject: osd: avoid unnecessary ref-counting across PrimaryLogPG::get_rw_locks.
X-Git-Tag: v13.1.0~349^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=423428aec801f475fb6146f862114b315b2986e5;p=ceph.git

osd: avoid unnecessary ref-counting across PrimaryLogPG::get_rw_locks.

Signed-off-by: Radoslaw Zarzynski <rzarzyns@redhat.com>
---

diff --git a/src/osd/PrimaryLogPG.cc b/src/osd/PrimaryLogPG.cc
index 13adf8330b82..f8f511b6ddd7 100644
--- a/src/osd/PrimaryLogPG.cc
+++ b/src/osd/PrimaryLogPG.cc
@@ -13846,11 +13846,12 @@ bool PrimaryLogPG::agent_maybe_evict(ObjectContextRef& obc, bool after_flush)
   dout(10) << __func__ << " evicting " << obc->obs.oi << dendl;
   OpContextUPtr ctx = simple_opc_create(obc);
 
+  auto null_op_req = OpRequestRef();
   if (!ctx->lock_manager.get_lock_type(
 	ObjectContext::RWState::RWWRITE,
 	obc->obs.oi.soid,
 	obc,
-	OpRequestRef())) {
+	null_op_req)) {
     close_op_ctx(ctx.release());
     dout(20) << __func__ << " skip (cannot get lock) " << obc->obs.oi << dendl;
     return false;
diff --git a/src/osd/osd_internal_types.h b/src/osd/osd_internal_types.h
index 4217767e677f..e02b76b79ec8 100644
--- a/src/osd/osd_internal_types.h
+++ b/src/osd/osd_internal_types.h
@@ -74,7 +74,7 @@ public:
       return get_state_name(state);
     }
 
-    list<OpRequestRef> waiters;  ///< ops waiting on state change
+    std::list<OpRequestRef> waiters;  ///< ops waiting on state change
     int count;              ///< number of readers or writers
 
     State state:4;               ///< rw state
@@ -89,11 +89,12 @@ public:
 	recovery_read_marker(false),
 	snaptrimmer_write_marker(false)
     {}
-    bool get_read(OpRequestRef op) {
+    bool get_read(OpRequestRef& op) {
       if (get_read_lock()) {
 	return true;
       } // else
-      waiters.push_back(op);
+      // Now we really need to bump up the ref-counter.
+      waiters.emplace_back(op);
       return false;
     }
     /// this function adjusts the counts if necessary
@@ -120,12 +121,12 @@ public:
       }
     }
 
-    bool get_write(OpRequestRef op, bool greedy=false) {
+    bool get_write(OpRequestRef& op, bool greedy=false) {
       if (get_write_lock(greedy)) {
 	return true;
       } // else
       if (op)
-	waiters.push_back(op);
+	waiters.emplace_back(op);
       return false;
     }
     bool get_write_lock(bool greedy=false) {
@@ -171,12 +172,12 @@ public:
 	return false;
       }
     }
-    bool get_excl(OpRequestRef op) {
+    bool get_excl(OpRequestRef& op) {
       if (get_excl_lock()) {
 	return true;
       } // else
       if (op)
-	waiters.push_back(op);
+	waiters.emplace_back(op);
       return false;
     }
     /// same as get_write_lock, but ignore starvation
@@ -211,16 +212,16 @@ public:
     bool empty() const { return state == RWNONE; }
   } rwstate;
 
-  bool get_read(OpRequestRef op) {
+  bool get_read(OpRequestRef& op) {
     return rwstate.get_read(op);
   }
-  bool get_write(OpRequestRef op) {
+  bool get_write(OpRequestRef& op) {
     return rwstate.get_write(op, false);
   }
   bool get_excl(OpRequestRef op) {
     return rwstate.get_excl(op);
   }
-  bool get_lock_type(OpRequestRef op, RWState::State type) {
+  bool get_lock_type(OpRequestRef& op, RWState::State type) {
     switch (type) {
     case RWState::RWWRITE:
       return get_write(op);
@@ -233,7 +234,7 @@ public:
       return true;
     }
   }
-  bool get_write_greedy(OpRequestRef op) {
+  bool get_write_greedy(OpRequestRef& op) {
     return rwstate.get_write(op, true);
   }
   bool get_snaptrimmer_write(bool mark_if_unsuccessful) {
@@ -348,7 +349,7 @@ class ObcLockManager {
     ObjectLockState(
       ObjectContextRef obc,
       ObjectContext::RWState::State type)
-      : obc(obc), type(type) {}
+      : obc(std::move(obc)), type(type) {}
   };
   map<hobject_t, ObjectLockState> locks;
 public:
@@ -362,8 +363,8 @@ public:
   bool get_lock_type(
     ObjectContext::RWState::State type,
     const hobject_t &hoid,
-    ObjectContextRef obc,
-    OpRequestRef op) {
+    ObjectContextRef& obc,
+    OpRequestRef& op) {
     assert(locks.find(hoid) == locks.end());
     if (obc->get_lock_type(op, type)) {
       locks.insert(make_pair(hoid, ObjectLockState(obc, type)));