crimson/osd: cache object_info and snapset in PGBackend

for better performance

Signed-off-by: Kefu Chai <kchai@redhat.com>

diff --git a/src/crimson/osd/pg.cc b/src/crimson/osd/pg.cc
index e7198545bf41b5e2d295920c5ee392f875a8f5f9..e16a07c1b42c63a26d481bbc70ca727233b5002f 100644 (file)
--- a/src/crimson/osd/pg.cc
+++ b/src/crimson/osd/pg.cc
@@ -1003,7 +1003,7 @@ seastar::future<Ref<MOSDOpReply>> PG::do_osd_ops(Ref<MOSDOp> m)
                         m->get_hobj().get_head() :
                         m->get_hobj());
       return backend->get_object(oid).then([&osd_op,this](auto oi) {
-        return do_osd_op(oi, &osd_op);
+        return do_osd_op(*oi, &osd_op);
       }).handle_exception_type([&osd_op](const object_not_found&) {
         osd_op.rval = -ENOENT;
         throw;

diff --git a/src/crimson/osd/pg_backend.cc b/src/crimson/osd/pg_backend.cc
index 8ceaddc9dae1addfc7553cf3f74c6cf755fa8200..ec1aa3495bf7e9449df906b0f3476a8527757faf 100644 (file)
--- a/src/crimson/osd/pg_backend.cc
+++ b/src/crimson/osd/pg_backend.cc
@@ -44,7 +44,8 @@ PGBackend::PGBackend(shard_id_t shard,
     store{store}
 {}
 
-seastar::future<object_info_t> PGBackend::get_object(const hobject_t& oid)
+seastar::future<PGBackend::cached_oi_t>
+PGBackend::get_object(const hobject_t& oid)
 {
   // want the head?
   if (oid.snap == CEPH_NOSNAP) {
@@ -52,23 +53,23 @@ seastar::future<object_info_t> PGBackend::get_object(const hobject_t& oid)
     return _load_oi(oid);
   } else {
     // we want a snap
-    return _load_ss(oid).then([oid,this](SnapSet ss) {
+    return _load_ss(oid).then([oid,this](cached_ss_t ss) {
       // head?
-      if (oid.snap > ss.seq) {
+      if (oid.snap > ss->seq) {
         return _load_oi(oid.get_head());
       } else {
         // which clone would it be?
-        auto clone = std::upper_bound(begin(ss.clones), end(ss.clones),
+        auto clone = std::upper_bound(begin(ss->clones), end(ss->clones),
                                       oid.snap);
-        if (clone == end(ss.clones)) {
+        if (clone == end(ss->clones)) {
           throw object_not_found{};
         }
         // clone
         auto soid = oid;
         soid.snap = *clone;
-        return _load_ss(soid).then([soid,this](SnapSet ss) {
-          auto clone_snap = ss.clone_snaps.find(soid.snap);
-          assert(clone_snap != end(ss.clone_snaps));
+        return _load_ss(soid).then([soid,this](cached_ss_t ss) {
+          auto clone_snap = ss->clone_snaps.find(soid.snap);
+          assert(clone_snap != end(ss->clone_snaps));
           if (clone_snap->second.empty()) {
             logger().trace("find_object: {}@[] -- DNE", soid);
             throw object_not_found{};
@@ -89,28 +90,38 @@ seastar::future<object_info_t> PGBackend::get_object(const hobject_t& oid)
   }
 }
 
-seastar::future<object_info_t> PGBackend::_load_oi(const hobject_t& oid)
+seastar::future<PGBackend::cached_oi_t>
+PGBackend::_load_oi(const hobject_t& oid)
 {
+  if (auto found = oi_cache.find(oid); found) {
+    return seastar::make_ready_future<cached_oi_t>(std::move(found));
+  }
   return store->get_attr(coll,
                          ghobject_t{oid, ghobject_t::NO_GEN, shard},
-                         OI_ATTR).then([this](auto bp) {
-    object_info_t oi;
+                         OI_ATTR).then([oid, this](auto bp) {
+    auto oi = std::make_unique<object_info_t>();
     bufferlist bl;
     bl.push_back(std::move(bp));
-    oi.decode(bl);
-    return seastar::make_ready_future<object_info_t>(std::move(oi));
+    oi->decode(bl);
+    return seastar::make_ready_future<cached_oi_t>(
+      oi_cache.insert(oid, std::move(oi)));
   });
 }
 
-seastar::future<SnapSet> PGBackend::_load_ss(const hobject_t& oid)
+seastar::future<PGBackend::cached_ss_t>
+PGBackend::_load_ss(const hobject_t& oid)
 {
+  if (auto found = ss_cache.find(oid); found) {
+    return seastar::make_ready_future<cached_ss_t>(std::move(found));
+  }
   return store->get_attr(coll,
                          ghobject_t{oid, ghobject_t::NO_GEN, shard},
-                         SS_ATTR).then([this](auto bp) {
+                         SS_ATTR).then([oid, this](auto bp) {
     bufferlist bl;
     bl.push_back(std::move(bp));
-    SnapSet snapset{bl};
-    return seastar::make_ready_future<SnapSet>(std::move(snapset));
+    auto snapset = std::make_unique<SnapSet>(bl);
+    return seastar::make_ready_future<cached_ss_t>(
+      ss_cache.insert(oid, std::move(snapset)));
   });
 }
 

diff --git a/src/crimson/osd/pg_backend.h b/src/crimson/osd/pg_backend.h
index 0ac8ff38ed9ce29fdb32ebe2f5686de73b8ee1ca..2774854f082197740bd18e8474585106836cd44d 100644 (file)
--- a/src/crimson/osd/pg_backend.h
+++ b/src/crimson/osd/pg_backend.h
@@ -6,7 +6,9 @@
 #include <map>
 #include <memory>
 #include <string>
+#include <boost/smart_ptr/local_shared_ptr.hpp>
 
+#include "crimson/common/shared_lru.h"
 #include "osd/osd_types.h"
 
 struct hobject_t;
@@ -28,7 +30,8 @@ public:
                                           const pg_pool_t& pool,
                                           ceph::os::CyanStore* store,
                                           const ec_profile_t& ec_profile);
-  seastar::future<object_info_t> get_object(const hobject_t& oid);
+  using cached_oi_t = boost::local_shared_ptr<object_info_t>;
+  seastar::future<cached_oi_t> get_object(const hobject_t& oid);
   seastar::future<bufferlist> read(const object_info_t& oi,
                                   uint64_t off,
                                   uint64_t len,
@@ -41,8 +44,11 @@ protected:
   ceph::os::CyanStore* store;
 
 private:
-  seastar::future<SnapSet> _load_ss(const hobject_t& oid);
-  seastar::future<object_info_t> _load_oi(const hobject_t& oid);
+  using cached_ss_t = boost::local_shared_ptr<SnapSet>;
+  SharedLRU<hobject_t, SnapSet> ss_cache;
+  seastar::future<cached_ss_t> _load_ss(const hobject_t& oid);
+  SharedLRU<hobject_t, object_info_t> oi_cache;
+  seastar::future<cached_oi_t> _load_oi(const hobject_t& oid);
   virtual seastar::future<bufferlist> _read(const hobject_t& hoid,
                                            size_t offset,
                                            size_t length,