Avoid using log_sys mutex when printing out show engine innodb status,

instead peek (maybe) old data.

1 files changed, 17 insertions, 2 deletions

diff --git a/storage/xtradb/include/log0log.ic b/storage/xtradb/include/log0log.ic
index bc076c954ad..853027daa7e 100644
--- a/storage/xtradb/include/log0log.ic
+++ b/storage/xtradb/include/log0log.ic
@@ -553,11 +553,27 @@ log_free_check(void)
 #endif /* !UNIV_HOTBACKUP */
 
 /****************************************************************//**
+Unsafely reads the log_sys->tracked_lsn value.  Uses atomic operations
+if available, or use dirty read. Use for printing only.
+
+@return log_sys->tracked_lsn value. */
+UNIV_INLINE
+lsn_t
+log_get_tracked_lsn_peek(void)
+/*==========================*/
+{
+#ifdef HAVE_ATOMIC_BUILTINS_64
+	return os_atomic_increment_uint64(&log_sys->tracked_lsn, 0);
+#else
+	return log_sys->tracked_lsn;
+#endif
+}
+
+/****************************************************************//**
 Safely reads the log_sys->tracked_lsn value.  Uses atomic operations
 if available, otherwise this field is protected with the log system
 mutex.  The writer counterpart function is log_set_tracked_lsn() in
 log0online.c.
-
 @return log_sys->tracked_lsn value. */
 UNIV_INLINE
 lsn_t
@@ -571,4 +587,3 @@ log_get_tracked_lsn(void)
 	return log_sys->tracked_lsn;
 #endif
 }
-