Index: percona-xtradb-cluster-5.5-5.5.37-25.10+dfsg/sql/log.cc
===================================================================
--- percona-xtradb-cluster-5.5-5.5.37-25.10+dfsg.orig/sql/log.cc	2016-05-24 19:59:34.526971789 +0000
+++ percona-xtradb-cluster-5.5-5.5.37-25.10+dfsg/sql/log.cc	2016-05-24 20:12:39.166420968 +0000
@@ -6779,7 +6779,7 @@
 
 static const char tc_log_magic[]={(char) 254, 0x23, 0x05, 0x74};
 
-ulong opt_tc_log_size= TC_LOG_MIN_SIZE;
+ulong opt_tc_log_size;
 ulong tc_log_max_pages_used=0, tc_log_page_size=0, tc_log_cur_pages_used=0;
 
 int TC_LOG_MMAP::open(const char *opt_name)
@@ -6792,7 +6792,6 @@
   DBUG_ASSERT(opt_name && opt_name[0]);
 
   tc_log_page_size= my_getpagesize();
-  DBUG_ASSERT(TC_LOG_PAGE_SIZE % tc_log_page_size == 0);
 
   fn_format(logname,opt_name,mysql_data_home,"",MY_UNPACK_FILENAME);
   if ((fd= mysql_file_open(key_file_tclog, logname, O_RDWR, MYF(0))) < 0)
Index: percona-xtradb-cluster-5.5-5.5.37-25.10+dfsg/sql/mysqld.cc
===================================================================
--- percona-xtradb-cluster-5.5-5.5.37-25.10+dfsg.orig/sql/mysqld.cc	2016-05-24 19:59:34.530971868 +0000
+++ percona-xtradb-cluster-5.5-5.5.37-25.10+dfsg/sql/mysqld.cc	2016-05-24 20:22:50.682513918 +0000
@@ -6860,12 +6860,6 @@
    "more than one storage engine, when binary log is disabled).",
    &opt_tc_log_file, &opt_tc_log_file, 0, GET_STR,
    REQUIRED_ARG, 0, 0, 0, 0, 0, 0},
-#ifdef HAVE_MMAP
-  {"log-tc-size", 0, "Size of transaction coordinator log.",
-   &opt_tc_log_size, &opt_tc_log_size, 0, GET_ULONG,
-   REQUIRED_ARG, TC_LOG_MIN_SIZE, TC_LOG_MIN_SIZE, ULONG_MAX, 0,
-   TC_LOG_PAGE_SIZE, 0},
-#endif
   {"master-info-file", 0,
    "The location and name of the file that remembers the master and where "
    "the I/O replication thread is in the master's binlogs.",
Index: percona-xtradb-cluster-5.5-5.5.37-25.10+dfsg/sql/sql_class.h
===================================================================
--- percona-xtradb-cluster-5.5-5.5.37-25.10+dfsg.orig/sql/sql_class.h	2016-05-24 19:59:34.514971552 +0000
+++ percona-xtradb-cluster-5.5-5.5.37-25.10+dfsg/sql/sql_class.h	2016-05-24 20:16:09.606564677 +0000
@@ -192,7 +192,6 @@
 
 
 #define TC_LOG_PAGE_SIZE   8192
-#define TC_LOG_MIN_SIZE    (3*TC_LOG_PAGE_SIZE)
 
 #define TC_HEURISTIC_RECOVER_COMMIT   1
 #define TC_HEURISTIC_RECOVER_ROLLBACK 2
Index: percona-xtradb-cluster-5.5-5.5.37-25.10+dfsg/sql/sys_vars.cc
===================================================================
--- percona-xtradb-cluster-5.5-5.5.37-25.10+dfsg.orig/sql/sys_vars.cc	2016-05-24 19:59:34.514971552 +0000
+++ percona-xtradb-cluster-5.5-5.5.37-25.10+dfsg/sql/sys_vars.cc	2016-05-24 20:34:55.313497182 +0000
@@ -4052,6 +4052,16 @@
        SESSION_ONLY(pseudo_slave_mode), NO_CMD_LINE, DEFAULT(FALSE),
        NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(check_pseudo_slave_mode));
 
+#ifdef HAVE_MMAP
+static Sys_var_ulong Sys_log_tc_size(
+       "log_tc_size",
+       "Size of transaction coordinator log.",
+       READ_ONLY GLOBAL_VAR(opt_tc_log_size),
+       CMD_LINE(REQUIRED_ARG),
+       VALID_RANGE(my_getpagesize() * 3, ULONG_MAX),
+       DEFAULT(my_getpagesize() * 6),
+       BLOCK_SIZE(my_getpagesize()));
+#endif
 
 /****************************************************************************
   Used templates