common/options.cc: Set Filestore rocksdb compaction readahead option.

fixes: http://tracker.ceph.com/issues/21505

Signed-off-by: Mark Nelson <mnelson@redhat.com>
(cherry picked from commit 66567e573836c570040c8d8148c34b0cf9dc9ce2)

Conflicts:
	src/common/options.cc (master commit made the change in
           src/common/options.cc, which doesn't exist in jewel)

diff --git a/src/common/config_opts.h b/src/common/config_opts.h
index 51a50eefe84a728d87450a2a5dafef2d805e0de5..cd13f219546bc3f31e53f9e5e56fe8bd20cd3900 100644 (file)
--- a/src/common/config_opts.h
+++ b/src/common/config_opts.h
@@ -860,7 +860,7 @@ OPTION(rocksdb_log_to_ceph_log, OPT_BOOL, true)  // log to ceph log
 OPTION(rocksdb_cache_size, OPT_INT, 128*1024*1024)  // default leveldb cache size
 OPTION(rocksdb_block_size, OPT_INT, 4*1024)  // default rocksdb block size
 // rocksdb options that will be used for omap(if omap_backend is rocksdb)
-OPTION(filestore_rocksdb_options, OPT_STR, "")
+OPTION(filestore_rocksdb_options, OPT_STR, "compaction_readahead_size=2097152")
 // rocksdb options that will be used in monstore
 OPTION(mon_rocksdb_options, OPT_STR, "write_buffer_size=33554432,compression=kNoCompression")