Parallel doublewrite memory not freed with innodb_fast_shutdown=2

[Laurynas Biveinis]

Presents as a Valgrind error on innodb.log_file_size_1:

./mtr --debug-server log_file_size_1 --valgrind-mysqld
...
108 bytes in 1 blocks are possibly lost in loss record 1 of 5
   at 0x4C2DB8F: malloc (vg_replace_malloc.c:299)
   by 0x1B28220: ut_allocator<unsigned char>::allocate(unsigned long, unsigned char const*, char const*, bool, bool) (ut0new.h:360)
   by 0x1DF8855: mem_strdup(char const*) (mem0mem.ic:578)
   by 0x1DFA879: buf_parallel_dblwr_make_path() (buf0dblwr.cc:422)
   by 0x1DFB2EA: buf_dblwr_init_or_load_pages(int, char const*) (buf0dblwr.cc:618)
   by 0x1EA93AA: SysTablespace::read_lsn_and_check_flags(unsigned long*) (fsp0sysspace.cc:575)
   by 0x1EAAB50: SysTablespace::open_or_create(bool, bool, unsigned long*, unsigned long*) (fsp0sysspace.cc:939)
   by 0x1D1340B: innobase_start_or_create_for_mysql() (srv0start.cc:1948)
   by 0x1B01FE6: innobase_init(void*) (ha_innodb.cc:4221)
   by 0xF8B1CF: ha_initialize_handlerton(st_plugin_int*) (handler.cc:870)
   by 0x1643F53: plugin_initialize(st_plugin_int*) (sql_plugin.cc:1184)
   by 0x1644B6A: plugin_init(int*, char**, int) (sql_plugin.cc:1528)
   by 0xEE4E52: init_server_components() (mysqld.cc:4235)
   by 0xEE64F0: mysqld_main(int, char**) (mysqld.cc:4914)
   by 0xEDD275: main (main.cc:25)

288 bytes in 2 blocks are possibly lost in loss record 2 of 5
   at 0x4C2DB8F: malloc (vg_replace_malloc.c:299)
   by 0x1B28220: ut_allocator<unsigned char>::allocate(unsigned long, unsigned char const*, char const*, bool, bool) (ut0new.h:360)
   by 0x1BF041D: os_event_create(char const*) (os0event.cc:461)
   by 0x1DFEA7A: buf_parallel_dblwr_create() (buf0dblwr.cc:1587)
   by 0x1D141F6: innobase_start_or_create_for_mysql() (srv0start.cc:2276)
   by 0x1B01FE6: innobase_init(void*) (ha_innodb.cc:4221)
   by 0xF8B1CF: ha_initialize_handlerton(st_plugin_int*) (handler.cc:870)
   by 0x1643F53: plugin_initialize(st_plugin_int*) (sql_plugin.cc:1184)
   by 0x1644B6A: plugin_init(int*, char**, int) (sql_plugin.cc:1528)
   by 0xEE4E52: init_server_components() (mysqld.cc:4235)
   by 0xEE64F0: mysqld_main(int, char**) (mysqld.cc:4914)
   by 0xEDD275: main (main.cc:25)

1,968 bytes in 2 blocks are possibly lost in loss record 3 of 5
   at 0x4C2FB55: calloc (vg_replace_malloc.c:711)
   by 0x1B28208: ut_allocator<unsigned char>::allocate(unsigned long, unsigned char const*, char const*, bool, bool) (ut0new.h:358)
   by 0x1DFEA4A: buf_parallel_dblwr_create() (buf0dblwr.cc:1578)
   by 0x1D141F6: innobase_start_or_create_for_mysql() (srv0start.cc:2276)
   by 0x1B01FE6: innobase_init(void*) (ha_innodb.cc:4221)
   by 0xF8B1CF: ha_initialize_handlerton(st_plugin_int*) (handler.cc:870)
   by 0x1643F53: plugin_initialize(st_plugin_int*) (sql_plugin.cc:1184)
   by 0x1644B6A: plugin_init(int*, char**, int) (sql_plugin.cc:1528)
   by 0xEE4E52: init_server_components() (mysqld.cc:4235)
   by 0xEE64F0: mysqld_main(int, char**) (mysqld.cc:4914)
   by 0xEDD275: main (main.cc:25)
...

[Laurynas Biveinis (laurynas-biveinis)]

https://github.com/percona/percona-server/pull/491

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PS-1707