From: Yan, Zheng <zheng.z.yan@intel.com>
Date: Fri, 9 May 2014 07:07:45 +0000 (+0800)
Subject: mds: try trimming exported objects
X-Git-Tag: v0.82~56^2~3
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=0bd4fa2ea817ba8d81c8a09b4bae37b8b4fe3c4b;p=ceph.git

mds: try trimming exported objects

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
---

diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc
index 4c9a1e530e92..1605fe147584 100644
--- a/src/mds/MDCache.cc
+++ b/src/mds/MDCache.cc
@@ -6188,12 +6188,17 @@ void MDCache::start_recovered_truncates()
  * however, we may expire a replica whose authority is recovering.
  * 
  */
-bool MDCache::trim(int max) 
+bool MDCache::trim(int max, int count)
 {
   // trim LRU
-  if (max < 0) {
+  if (count > 0) {
+    max = lru.lru_get_size() - count;
+    if (max <= 0)
+      max = 1;
+  } else if (max < 0) {
     max = g_conf->mds_cache_size;
-    if (!max) return false;
+    if (max <= 0)
+      return false;
   }
   dout(7) << "trim max=" << max << "  cur=" << lru.lru_get_size() << dendl;
 
diff --git a/src/mds/MDCache.h b/src/mds/MDCache.h
index 225cce0519b4..bd823429f5fa 100644
--- a/src/mds/MDCache.h
+++ b/src/mds/MDCache.h
@@ -565,7 +565,7 @@ public:
   size_t get_cache_size() { return lru.lru_get_size(); }
 
   // trimming
-  bool trim(int max = -1);   // trim cache
+  bool trim(int max=-1, int count=-1);   // trim cache
   bool trim_dentry(CDentry *dn, map<int, MCacheExpire*>& expiremap);
   void trim_dirfrag(CDir *dir, CDir *con,
 		    map<int, MCacheExpire*>& expiremap);
@@ -659,7 +659,8 @@ public:
   }
   void touch_dentry_bottom(CDentry *dn) {
     lru.lru_bottouch(dn);
-    if (dn->get_projected_linkage()->is_primary()) {
+    if (dn->get_projected_linkage()->is_primary() &&
+	dn->get_dir()->inode->is_stray()) {
       CInode *in = dn->get_projected_linkage()->get_inode();
       if (in->has_dirfrags()) {
 	list<CDir*> ls;
diff --git a/src/mds/Migrator.cc b/src/mds/Migrator.cc
index 11475846d996..f23ea3bf43f1 100644
--- a/src/mds/Migrator.cc
+++ b/src/mds/Migrator.cc
@@ -1461,7 +1461,7 @@ int Migrator::encode_export_dir(bufferlist& exportbl,
 
 void Migrator::finish_export_dir(CDir *dir, utime_t now, int peer,
 				 map<inodeno_t,map<client_t,Capability::Import> >& peer_imported,
-				 list<Context*>& finished)
+				 list<Context*>& finished, int *num_dentries)
 {
   dout(10) << "finish_export_dir " << *dir << dendl;
 
@@ -1500,11 +1500,14 @@ void Migrator::finish_export_dir(CDir *dir, utime_t now, int peer,
       // subdirs?
       in->get_nested_dirfrags(subdirs);
     }
+
+    cache->touch_dentry_bottom(dn); // move dentry to tail of LRU
+    ++(*num_dentries);
   }
 
   // subdirs
   for (list<CDir*>::iterator it = subdirs.begin(); it != subdirs.end(); ++it) 
-    finish_export_dir(*it, now, peer, peer_imported, finished);
+    finish_export_dir(*it, now, peer, peer_imported, finished, num_dentries);
 }
 
 class C_MDS_ExportFinishLogged : public Context {
@@ -1765,9 +1768,10 @@ void Migrator::export_finish(CDir *dir)
   assert(g_conf->mds_kill_export_at != 13);
   
   // finish export (adjust local cache state)
+  int num_dentries = 0;
   C_Contexts *fin = new C_Contexts(g_ceph_context);
-  finish_export_dir(dir, ceph_clock_now(g_ceph_context),
-		    it->second.peer, it->second.peer_imported, fin->contexts);
+  finish_export_dir(dir, ceph_clock_now(g_ceph_context), it->second.peer,
+		    it->second.peer_imported, fin->contexts, &num_dentries);
   dir->add_waiter(CDir::WAIT_UNFREEZE, fin);
 
   // unfreeze
@@ -1816,6 +1820,8 @@ void Migrator::export_finish(CDir *dir)
   cache->show_subtrees();
   audit();
 
+  cache->trim(-1, num_dentries); // try trimming exported dentries
+
   // send pending import_maps?
   mds->mdcache->maybe_send_pending_resolves();
   
@@ -2329,6 +2335,7 @@ void Migrator::import_reverse(CDir *dir)
       !dir->get_inode()->has_subtree_root_dirfrag(mds->get_nodeid()))
     dir->get_inode()->clear_scatter_dirty();
 
+  int num_dentries = 0;
   // adjust auth bits.
   list<CDir*> q;
   q.push_back(dir);
@@ -2381,6 +2388,9 @@ void Migrator::import_reverse(CDir *dir)
 	  if (bounds.count(*p) == 0)
 	    q.push_back(*p);
       }
+
+      cache->touch_dentry_bottom(dn); // move dentry to tail of LRU
+      ++num_dentries;
     }
   }
 
@@ -2414,6 +2424,8 @@ void Migrator::import_reverse(CDir *dir)
 
   cache->try_subtree_merge(dir);  // NOTE: this may journal subtree map as side effect
 
+  cache->trim(-1, num_dentries); // try trimming dentries
+
   // bystanders?
   if (stat.bystanders.empty()) {
     dout(7) << "no bystanders, finishing reverse now" << dendl;
diff --git a/src/mds/Migrator.h b/src/mds/Migrator.h
index f9cb078e3743..22a4c071961a 100644
--- a/src/mds/Migrator.h
+++ b/src/mds/Migrator.h
@@ -257,7 +257,7 @@ public:
 			utime_t now);
   void finish_export_dir(CDir *dir, utime_t now, int target,
 			 map<inodeno_t,map<client_t,Capability::Import> >& peer_imported,
-			 list<Context*>& finished);
+			 list<Context*>& finished, int *num_dentries);
 
   void add_export_finish_waiter(CDir *dir, Context *c) {
     map<CDir*, export_state_t>::iterator it = export_state.find(dir);