Turn off readahead on main mmap

It's harmful when the DB is larger than RAM.
12 years ago · b1da555c4c
parent d74330128a
commit b1da555c4c
1 changed files with 2 additions and 0 deletions
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@ -2870,6 +2870,8 @@ mdb_env_open2(MDB_env *env)
 		env->me_map = NULL;
 		return ErrCode();
 	}
+	/* Turn off readahead. It's harmful when the DB is larger than RAM. */
+	posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);
 #endif

 	if (newenv) {