osdc/Objecter: avoid vector copies in _calc_target

Use std::move on temporary vector to claim its elements,
instead of copying them.

Signed-off-by: Or Ozeri <oro@il.ibm.com>

diff --git a/src/osdc/Objecter.cc b/src/osdc/Objecter.cc
index f66ba9fdcad219d97cf211985e0a106ca3cd0f30..a20384e8870a7880d3dd66c075f9cdaba1dbac87 100644 (file)
--- a/src/osdc/Objecter.cc
+++ b/src/osdc/Objecter.cc
@@ -2761,14 +2761,8 @@ int Objecter::_calc_target(op_target_t *t, Connection *con, bool any_change)
   vector<int> up, acting;
   ps_t actual_ps = ceph_stable_mod(pgid.ps(), pg_num, pg_num_mask);
   pg_t actual_pgid(actual_ps, pgid.pool());
-  pg_mapping_t pg_mapping;
-  pg_mapping.epoch = osdmap->get_epoch();
-  if (lookup_pg_mapping(actual_pgid, &pg_mapping)) {
-    up = pg_mapping.up;
-    up_primary = pg_mapping.up_primary;
-    acting = pg_mapping.acting;
-    acting_primary = pg_mapping.acting_primary;
-  } else {
+  if (!lookup_pg_mapping(actual_pgid, osdmap->get_epoch(), &up, &up_primary,
+                         &acting, &acting_primary)) {
     osdmap->pg_to_up_acting_osds(actual_pgid, &up, &up_primary,
                                  &acting, &acting_primary);
     pg_mapping_t pg_mapping(osdmap->get_epoch(),
@@ -2838,10 +2832,10 @@ int Objecter::_calc_target(op_target_t *t, Connection *con, bool any_change)
 
   if (legacy_change || split_or_merge || force_resend) {
     t->pgid = pgid;
-    t->acting = acting;
+    t->acting = std::move(acting);
     t->acting_primary = acting_primary;
     t->up_primary = up_primary;
-    t->up = up;
+    t->up = std::move(up);
     t->size = size;
     t->min_size = min_size;
     t->pg_num = pg_num;
@@ -2849,8 +2843,8 @@ int Objecter::_calc_target(op_target_t *t, Connection *con, bool any_change)
     t->pg_num_pending = pg_num_pending;
     spg_t spgid(actual_pgid);
     if (pi->is_erasure()) {
-      for (uint8_t i = 0; i < acting.size(); ++i) {
-        if (acting[i] == acting_primary) {
+      for (uint8_t i = 0; i < t->acting.size(); ++i) {
+        if (t->acting[i] == acting_primary) {
           spgid.reset_shard(shard_id_t(i));
           break;
         }
@@ -2865,31 +2859,31 @@ int Objecter::_calc_target(op_target_t *t, Connection *con, bool any_change)
     t->peering_crush_mandatory_member = pi->peering_crush_mandatory_member;
     ldout(cct, 10) << __func__ << " "
                   << " raw pgid " << pgid << " -> actual " << t->actual_pgid
-                  << " acting " << acting
+                  << " acting " << t->acting
                   << " primary " << acting_primary << dendl;
     t->used_replica = false;
     if ((t->flags & (CEPH_OSD_FLAG_BALANCE_READS |
                      CEPH_OSD_FLAG_LOCALIZE_READS)) &&
-        !is_write && pi->is_replicated() && acting.size() > 1) {
+        !is_write && pi->is_replicated() && t->acting.size() > 1) {
       int osd;
-      ceph_assert(is_read && acting[0] == acting_primary);
+      ceph_assert(is_read && t->acting[0] == acting_primary);
       if (t->flags & CEPH_OSD_FLAG_BALANCE_READS) {
-       int p = rand() % acting.size();
+       int p = rand() % t->acting.size();
        if (p)
          t->used_replica = true;
-       osd = acting[p];
-       ldout(cct, 10) << " chose random osd." << osd << " of " << acting
+       osd = t->acting[p];
+       ldout(cct, 10) << " chose random osd." << osd << " of " << t->acting
                       << dendl;
       } else {
        // look for a local replica.  prefer the primary if the
        // distance is the same.
        int best = -1;
        int best_locality = 0;
-       for (unsigned i = 0; i < acting.size(); ++i) {
+       for (unsigned i = 0; i < t->acting.size(); ++i) {
          int locality = osdmap->crush->get_common_ancestor_distance(
-                cct, acting[i], crush_location);
+                cct, t->acting[i], crush_location);
          ldout(cct, 20) << __func__ << " localize: rank " << i
-                        << " osd." << acting[i]
+                        << " osd." << t->acting[i]
                         << " locality " << locality << dendl;
          if (i == 0 ||
              (locality >= 0 && best_locality >= 0 &&
@@ -2902,7 +2896,7 @@ int Objecter::_calc_target(op_target_t *t, Connection *con, bool any_change)
          }
        }
        ceph_assert(best >= 0);
-       osd = acting[best];
+       osd = t->acting[best];
       }
       t->osd = osd;
     } else {

diff --git a/src/osdc/Objecter.h b/src/osdc/Objecter.h
index e4c7ab4b4b6af24699ccacd03580a832365ff825..4226bfb9be4a16e76b4d1367f8017d0f1504866a 100644 (file)
--- a/src/osdc/Objecter.h
+++ b/src/osdc/Objecter.h
@@ -1666,8 +1666,8 @@ private:
     int acting_primary = -1;
 
     pg_mapping_t() {}
-    pg_mapping_t(epoch_t epoch, std::vector<int> up, int up_primary,
-                 std::vector<int> acting, int acting_primary)
+    pg_mapping_t(epoch_t epoch, const std::vector<int>& up, int up_primary,
+                 const std::vector<int>& acting, int acting_primary)
                : epoch(epoch), up(up), up_primary(up_primary),
                  acting(acting), acting_primary(acting_primary) {}
   };
@@ -1677,7 +1677,9 @@ private:
   std::map<int64_t, std::vector<pg_mapping_t>> pg_mappings;
 
   // convenient accessors
-  bool lookup_pg_mapping(const pg_t& pg, pg_mapping_t* pg_mapping) {
+  bool lookup_pg_mapping(const pg_t& pg, epoch_t epoch, std::vector<int> *up,
+                         int *up_primary, std::vector<int> *acting,
+                         int *acting_primary) {
     std::shared_lock l{pg_mapping_lock};
     auto it = pg_mappings.find(pg.pool());
     if (it == pg_mappings.end())
@@ -1685,9 +1687,13 @@ private:
     auto& mapping_array = it->second;
     if (pg.ps() >= mapping_array.size())
       return false;
-    if (mapping_array[pg.ps()].epoch != pg_mapping->epoch) // stale
+    if (mapping_array[pg.ps()].epoch != epoch) // stale
       return false;
-    *pg_mapping = mapping_array[pg.ps()];
+    auto& pg_mapping = mapping_array[pg.ps()];
+    *up = pg_mapping.up;
+    *up_primary = pg_mapping.up_primary;
+    *acting = pg_mapping.acting;
+    *acting_primary = pg_mapping.acting_primary;
     return true;
   }
   void update_pg_mapping(const pg_t& pg, pg_mapping_t&& pg_mapping) {