FileStore: add option to cap alloc hint size

Add a new config option, filestore_max_alloc_hint_size, to cap SETALLOCHINT hint size. The unit is a byte, the default value is 1 megabyte. Signed-off-by: Ilya Dryomov <[email protected]>
dano · Mar 3, 2014 · 8e49bc3 · 8e49bc3
1 parent 1f5b796
commit 8e49bc3
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Showing 3 changed files with 8 additions and 1 deletion.
diff --git a/src/common/config_opts.h b/src/common/config_opts.h
@@ -616,6 +616,8 @@ OPTION(filestore_max_inline_xattrs_other, OPT_U32, 2)
 OPTION(filestore_sloppy_crc, OPT_BOOL, false)         // track sloppy crcs
 OPTION(filestore_sloppy_crc_block_size, OPT_INT, 65536)
 
+OPTION(filestore_max_alloc_hint_size, OPT_U64, 1ULL << 20) // bytes
+
 OPTION(filestore_max_sync_interval, OPT_DOUBLE, 5)    // seconds
 OPTION(filestore_min_sync_interval, OPT_DOUBLE, .01)  // seconds
 OPTION(filestore_btrfs_snap, OPT_BOOL, true)

diff --git a/src/os/FileStore.cc b/src/os/FileStore.cc
@@ -461,6 +461,7 @@ FileStore::FileStore(const std::string &base, const std::string &jdev, const cha
   m_filestore_dump_fmt(true),
   m_filestore_sloppy_crc(g_conf->filestore_sloppy_crc),
   m_filestore_sloppy_crc_block_size(g_conf->filestore_sloppy_crc_block_size),
+  m_filestore_max_alloc_hint_size(g_conf->filestore_max_alloc_hint_size),
   m_fs_type(FS_TYPE_NONE),
   m_filestore_max_inline_xattr_size(0),
   m_filestore_max_inline_xattrs(0)
@@ -4727,7 +4728,7 @@ int FileStore::_set_alloc_hint(coll_t cid, const ghobject_t& oid,
 
   {
     // TODO: a more elaborate hint calculation
-    uint64_t hint = expected_write_size;
+    uint64_t hint = MIN(expected_write_size, m_filestore_max_alloc_hint_size);
 
     ret = backend->set_alloc_hint(**fd, hint);
     dout(20) << "set_alloc_hint hint " << hint << " ret " << ret << dendl;
@@ -4756,6 +4757,7 @@ const char** FileStore::get_tracked_conf_keys() const
     "filestore_replica_fadvise",
     "filestore_sloppy_crc",
     "filestore_sloppy_crc_block_size",
+    "filestore_max_alloc_hint_size",
     NULL
   };
   return KEYS;
@@ -4785,6 +4787,7 @@ void FileStore::handle_conf_change(const struct md_config_t *conf,
       changed.count("filestore_fail_eio") ||
       changed.count("filestore_sloppy_crc") ||
       changed.count("filestore_sloppy_crc_block_size") ||
+      changed.count("filestore_max_alloc_hint_size") ||
       changed.count("filestore_replica_fadvise")) {
     Mutex::Locker l(lock);
     m_filestore_min_sync_interval = conf->filestore_min_sync_interval;
@@ -4798,6 +4801,7 @@ void FileStore::handle_conf_change(const struct md_config_t *conf,
     m_filestore_replica_fadvise = conf->filestore_replica_fadvise;
     m_filestore_sloppy_crc = conf->filestore_sloppy_crc;
     m_filestore_sloppy_crc_block_size = conf->filestore_sloppy_crc_block_size;
+    m_filestore_max_alloc_hint_size = conf->filestore_max_alloc_hint_size;
   }
   if (changed.count("filestore_commit_timeout")) {
     Mutex::Locker l(sync_entry_timeo_lock);

diff --git a/src/os/FileStore.h b/src/os/FileStore.h
@@ -612,6 +612,7 @@ class FileStore : public JournalingObjectStore,
   atomic_t m_filestore_kill_at;
   bool m_filestore_sloppy_crc;
   int m_filestore_sloppy_crc_block_size;
+  uint64_t m_filestore_max_alloc_hint_size;
   enum fs_types m_fs_type;
 
   //Determined xattr handling based on fs type