The interesting thread is 37:
Thread 37 (LWP 15806): +bt #0 0x000000363720b43c in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0 #1 0x0000000000ac4143 in os_cond_wait (fast_mutex=0x27e6c30, cond=0x27e6c70) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/os/os0sync.cc:214 #2 os_event_wait_low (event=0x27e6c30, reset_sig_count=264) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/os/os0sync.cc:610 #3 0x0000000000b63601 in sync_array_wait_event (arr=0x20e3460, index=0) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/sync/sync0arr.cc:433 #4 0x0000000000b653a6 in rw_lock_s_lock_spin (_lock=0x27e6a38, pass=0, priority_lock=true, high_priority=false, file_name=0xe1eb90 "/bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/btr/btr0sea.cc", line=954) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/sync/sync0rw.cc:537 #5 0x0000000000bc60ae in pfs_rw_lock_s_lock_func (line=954, file_name=0xe1eb90 "/bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/btr/btr0sea.cc", lock=0x27e6a38, pass=<optimized out>) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/include/sync0rw.ic:1090 #6 btr_search_guess_on_hash (index=0x280c2b8, info=0x280c670, tuple=0x7fc2e40595d8, mode=4, latch_mode=2, cursor=0x7fc3f08230b0, has_search_latch=0, mtr=0x7fc3f08228c0) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/btr/btr0sea.cc:954 #7 0x0000000000bb7680 in btr_cur_search_to_nth_level (index=0x280c2b8, level=0, tuple=0x7fc2e40595d8, mode=4, latch_mode=2, cursor=0x7fc3f08230b0, has_search_latch=0, file=0xe04590 "/bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/row/row0ins.cc", line=2370, mtr=0x7fc3f08228c0) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/btr/btr0cur.cc:539 #8 0x0000000000b09b8e in row_ins_clust_index_entry_low (flags=0, mode=2, index=0x280c2b8, n_uniq=2, entry=0x7fc2e40595d8, n_ext=0, thr=0x7fc2e4050370) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/row/row0ins.cc:2370 #9 0x0000000000b0e825 in row_ins_clust_index_entry (index=0x280c2b8, entry=0x7fc2e40595d8, thr=0x7fc2e4050370, n_ext=0) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/row/row0ins.cc:2909 #10 0x0000000000b0ee07 in row_ins_index_entry (thr=0x7fc2e4050370, entry=0x7fc2e40595d8, index=0x280c2b8) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/row/row0ins.cc:3003 #11 row_ins_index_entry_step (thr=0x7fc2e4050370, node=0x7fc2e40d3d20) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/row/row0ins.cc:3080 #12 row_ins (thr=0x7fc2e4050370, node=0x7fc2e40d3d20) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/row/row0ins.cc:3220 #13 row_ins_step (thr=0x7fc2e4050370) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/row/row0ins.cc:3345 #14 0x0000000000aec6c8 in que_thr_step (thr=0x7fc2e4050370) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/que/que0que.cc:1095 #15 que_run_threads_low (thr=0x7fc2e4050370) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/que/que0que.cc:1177 #16 0x0000000000aece50 in que_run_threads (thr=0x7fc2e4050370) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/que/que0que.cc:1218 #17 0x0000000000b2678d in row_create_table_for_mysql (table=0x7fc2e40bcf78, trx=0x7fc2e40f5c78, commit=false) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/row/row0mysql.cc:2264 #18 0x0000000000a565b1 in create_table_def (flags2=1024, flags=1, remote_path=0x100 <Address 0x100 out of bounds>, temp_path=0x0, table_name=0x7fc3f0823aa0 "test/e", form=0x7fc3f0823d80, trx=0x7fc2e40f5c78) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/handler/ha_innodb.cc:9143 #19 ha_innobase::create (this=<optimized out>, name=0x400 <Address 0x400 out of bounds>, form=0x7fc3f0823d80, create_info=<optimized out>) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/handler/ha_innodb.cc:10037 #20 0x00000000005c0bae in ha_create_table (thd=0x2a10d50, path=<optimized out>, db=0x7fc2e80053f8 "test", table_name=0x7fc2e8004e60 "e", create_info=0x7fc3f0827890, update_create_info=false, is_temp_table=false) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/handler.cc:4882 #21 0x00000000007d8766 in rea_create_table (thd=0x2a10d50, path=0x7fc3f0825e40 "./test/e", db=0x7fc2e80053f8 "test", table_name=0x7fc2e8004e60 "e", create_info=0x7fc3f0827890, create_fields=..., keys=0, key_info=0x7fc2e413a698, file=0x7fc2e4138980, no_ha_table=false) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/unireg.cc:526 #22 0x000000000077c159 in create_table_impl (thd=0x2a10d50, db=0x7fc2e80053f8 "test", table_name=0x7fc2e8004e60 "e", path=0x7fc3f0825e40 "./test/e", create_info=0x7fc3f0827890, alter_info=0x7fc3f0827290, internal_tmp_table=false, select_field_count=43, no_ha_table=false, is_trans=0x0, key_info=0x7fc3f0826050, key_count=0x7fc3f0826058) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/sql_table.cc:4847 #23 0x000000000077cb57 in mysql_create_table_no_lock (thd=0x2a10d50, db=0x7fc2e80053f8 "test", table_name=0x7fc2e8004e60 "e", create_info=0x7fc3f0827890, alter_info=0x7fc3f0827290, select_field_count=43, is_trans=0x0) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/sql_table.cc:4959 #24 0x0000000000702f45 in create_table_from_items (thd=0x2a10d50, create_info=0x7fc3f0827890, create_table=0x7fc2e8004e98, alter_info=0x7fc3f0827290, items=<optimized out>) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/sql_insert.cc:4050 #25 0x00000000007031d4 in select_create::prepare (this=0x7fc2e40e58a0, values=..., u=0x2a13208) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/sql_insert.cc:4118 #26 0x000000000074314f in JOIN::prepare (this=0x7fc2e40e5a20, tables_init=<optimized out>, wild_num=44120432, conds_init=<optimized out>, og_num=0, order_init=<optimized out>, group_init=0x0, having_init=0x0, select_lex_arg=0x2a13850, unit_arg=0x2a13208) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/sql_resolver.cc:335 #27 0x000000000074b9fa in mysql_prepare_select (free_join=<optimized out>, select_lex=0x2a13850, unit=0x2a13208, result=0x7fc2e40e58a0, select_options=2416184064, having=0x0, group=0x0, order=0x0, og_num=0, conds=0x0, fields=..., wild_num=1, tables=0x7fc2e80055d0, thd=0x2a10d50) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/sql_select.cc:1055 #28 mysql_select (thd=0x2a10d50, tables=0x7fc2e80055d0, wild_num=1, fields=..., conds=0x0, order=<optimized out>, group=0x2a13950, having=0x0, select_options=2416184064, result=0x7fc2e40e58a0, unit=0x2a13208, select_lex=0x2a13850) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/sql_select.cc:1178 #29 0x000000000074bdbb in handle_select (thd=0x2a10d50, result=0x7fc2e40e58a0, setup_tables_done_option=0) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/sql_select.cc:111 #30 0x0000000000727dd5 in mysql_execute_command (thd=0x2a10d50) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/sql_parse.cc:3330 #31 0x0000000000729328 in mysql_parse (thd=0x2a10d50, rawbuf=0x2a13140 "Pc9\001", length=<optimized out>, parser_state=<optimized out>) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/sql_parse.cc:6569 #32 0x000000000072a48c in dispatch_command (command=COM_QUERY, thd=0x2a10d50, packet=0x7fc3f0828910 "P\r\241\002", packet_length=57) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/sql_parse.cc:1436 #33 0x000000000072b687 in do_command (thd=0x2a10d50) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/sql_parse.cc:1051 #34 0x00000000007d8c07 in threadpool_process_request (thd=0x2a10d50) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/threadpool_common.cc:316 #35 0x00000000007db918 in handle_event (connection=0x291e390) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/threadpool_unix.cc:1468 #36 worker_main (param=0x1527e00 <all_groups+1024>) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/sql/threadpool_unix.cc:1521 #37 0x0000000000a2cdda in pfs_spawn_thread (arg=0x7fc2ec00c110) at /bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/perfschema/pfs.cc:1858 #38 0x0000003637207851 in start_thread () from /lib64/libpthread.so.0 #39 0x0000003636ee890d in clone () from /lib64/libc.so.6
It is waiting to S-latch the the btr latch part, but no other thread holds it, thus a missed wakeup event.
(gdb) print/x (*(prio_rw_lock_t *)cell->wait_object).base_lock->lock_word $17 = 0x100000 - unlocked
(gdb) print event $14 = (os_event_t) 0x27e6c30 - equal to lock->event below
(gdb) print *(prio_rw_lock_t *)cell->wait_object $13 = {base_lock = {lock_word = 1048576, waiters = 1, recursive = 0, writer_thread = 140478917900032, event = 0x27e6c30, wait_ex_event = 0x27e6cc0, list = {prev = 0x27e82a0, next = 0x27d24c0}, debug_list = {count = 0, start = 0x0, end = 0x0}, level = 160, pfs_psi = 0x0, count_os_wait = 264, lock_name = 0xe1f3cf "&btr_search_latch_arr[i]", last_s_file_name = 0xe1eb90 "/bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/btr/btr0sea.cc", last_x_file_name = 0xe1eb90 "/bzr/5.6_dbg/Percona-Server-5.6.13-rc60.6/storage/innobase/btr/btr0sea.cc", writer_is_wait_ex = 0, last_s_line = 954, last_x_line = 1653, magic_n = 22643}, high_priority_s_waiters = 0, high_priority_s_event = 0x27e6d50, high_priority_x_waiters = 0, high_priority_x_event = 0x27e6de0, high_priority_wait_ex_waiter = 1}
The interesting thread is 37:
Thread 37 (LWP 15806): cond_wait@ @GLIBC_ 2.3.2 () from /lib64/ libpthread. so.0 0x27e6c30, cond=0x27e6c70) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ os/os0sync. cc:214 count=264) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ os/os0sync. cc:610 wait_event (arr=0x20e3460, index=0) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ sync/sync0arr. cc:433 false, file_name=0xe1eb90 "/bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ btr/btr0sea. cc", line=954) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ sync/sync0rw. cc:537 lock_s_ lock_func (line=954, file_name=0xe1eb90 "/bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ btr/btr0sea. cc", lock=0x27e6a38, pass=<optimized out>) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ include/ sync0rw. ic:1090 guess_on_ hash (index=0x280c2b8, info=0x280c670, tuple=0x7fc2e40 595d8, mode=4, latch_mode=2, cursor= 0x7fc3f08230b0, has_search_latch=0, mtr=0x7fc3f08228c0) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ btr/btr0sea. cc:954 search_ to_nth_ level (index=0x280c2b8, level=0, tuple=0x7fc2e40 595d8, mode=4, latch_mode=2, cursor= 0x7fc3f08230b0, has_search_latch=0, file=0xe04590 "/bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ row/row0ins. cc", line=2370, mtr=0x7fc3f08228c0) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ btr/btr0cur. cc:539 clust_index_ entry_low (flags=0, mode=2, index=0x280c2b8, n_uniq=2, entry=0x7fc2e40 595d8, n_ext=0, thr=0x7fc2e4050370) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ row/row0ins. cc:2370 clust_index_ entry (index=0x280c2b8, entry=0x7fc2e40 595d8, thr=0x7fc2e4050370, n_ext=0) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ row/row0ins. cc:2909 0370, entry=0x7fc2e40 595d8, index=0x280c2b8) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ row/row0ins. cc:3003 index_entry_ step (thr=0x7fc2e405 0370, node=0x7fc2e40d 3d20) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ row/row0ins. cc:3080 0370, node=0x7fc2e40d 3d20) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ row/row0ins. cc:3220 0370) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ row/row0ins. cc:3345 0370) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ que/que0que. cc:1095 0370) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ que/que0que. cc:1177 0370) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ que/que0que. cc:1218 table_for_ mysql (table= 0x7fc2e40bcf78, trx=0x7fc2e40f5c78, commit=false) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ row/row0mysql. cc:2264 0x7fc3f0823aa0 "test/e", form=0x7fc3f082 3d80, trx=0x7fc2e40f5c78) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ handler/ ha_innodb. cc:9143 3d80, create_ info=<optimized out>) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ handler/ ha_innodb. cc:10037 0x7fc2e8004e60 "e", create_ info=0x7fc3f082 7890, update_ create_ info=false, is_temp_ table=false) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/handler. cc:4882 0x7fc2e8004e60 "e", create_ info=0x7fc3f082 7890, create_fields=..., keys=0, key_info= 0x7fc2e413a698, file=0x7fc2e413 8980, no_ha_table=false) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/unireg. cc:526 0x7fc2e8004e60 "e", path=0x7fc3f0825e40 "./test/e", create_ info=0x7fc3f082 7890, alter_info= 0x7fc3f0827290, internal_ tmp_table= false, select_ field_count= 43, no_ha_table=false, is_trans=0x0, key_info= 0x7fc3f0826050, key_count= 0x7fc3f0826058) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/sql_ table.cc: 4847 table_no_ lock (thd=0x2a10d50, db=0x7fc2e80053f8 "test", table_name= 0x7fc2e8004e60 "e", create_ info=0x7fc3f082 7890, alter_info= 0x7fc3f0827290, select_ field_count= 43, is_trans=0x0) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/sql_ table.cc: 4959 table_from_ items (thd=0x2a10d50, create_ info=0x7fc3f082 7890, create_ table=0x7fc2e80 04e98, alter_info= 0x7fc3f0827290, items=<optimized out>) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/sql_ insert. cc:4050 create: :prepare (this=0x7fc2e40 e58a0, values=..., u=0x2a13208) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/sql_ insert. cc:4118 e5a20, tables_ init=<optimized out>, wild_num=44120432, conds_init= <optimized out>, og_num=0, order_init= <optimized out>, group_init=0x0, having_init=0x0, select_ lex_arg= 0x2a13850, unit_arg=0x2a13208) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/sql_ resolver. cc:335 select (free_join= <optimized out>, select_ lex=0x2a13850, unit=0x2a13208, result= 0x7fc2e40e58a0, select_ options= 2416184064, having=0x0, group=0x0, order=0x0, og_num=0, conds=0x0, fields=..., wild_num=1, tables= 0x7fc2e80055d0, thd=0x2a10d50) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/sql_ select. cc:1055 0x7fc2e80055d0, wild_num=1, fields=..., conds=0x0, order=<optimized out>, group=0x2a13950, having=0x0, select_ options= 2416184064, result= 0x7fc2e40e58a0, unit=0x2a13208, select_ lex=0x2a13850) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/sql_ select. cc:1178 0x7fc2e40e58a0, setup_tables_ done_option= 0) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/sql_ select. cc:111 command (thd=0x2a10d50) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/sql_ parse.cc: 3330 state=< optimized out>) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/sql_ parse.cc: 6569 0x7fc3f0828910 "P\r\241\002", packet_length=57) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/sql_ parse.cc: 1436 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/sql_ parse.cc: 1051 process_ request (thd=0x2a10d50) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/threadpool_ common. cc:316 0x291e390) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/threadpool_ unix.cc: 1468 6_dbg/Percona- Server- 5.6.13- rc60.6/ sql/threadpool_ unix.cc: 1521 c110) at /bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ perfschema/ pfs.cc: 1858 libpthread. so.0
+bt
#0 0x000000363720b43c in pthread_
#1 0x0000000000ac4143 in os_cond_wait (fast_mutex=
#2 os_event_wait_low (event=0x27e6c30, reset_sig_
#3 0x0000000000b63601 in sync_array_
#4 0x0000000000b653a6 in rw_lock_s_lock_spin (_lock=0x27e6a38, pass=0, priority_lock=true, high_priority=
#5 0x0000000000bc60ae in pfs_rw_
#6 btr_search_
#7 0x0000000000bb7680 in btr_cur_
#8 0x0000000000b09b8e in row_ins_
#9 0x0000000000b0e825 in row_ins_
#10 0x0000000000b0ee07 in row_ins_index_entry (thr=0x7fc2e405
#11 row_ins_
#12 row_ins (thr=0x7fc2e405
#13 row_ins_step (thr=0x7fc2e405
#14 0x0000000000aec6c8 in que_thr_step (thr=0x7fc2e405
#15 que_run_threads_low (thr=0x7fc2e405
#16 0x0000000000aece50 in que_run_threads (thr=0x7fc2e405
#17 0x0000000000b2678d in row_create_
#18 0x0000000000a565b1 in create_table_def (flags2=1024, flags=1, remote_path=0x100 <Address 0x100 out of bounds>, temp_path=0x0, table_name=
#19 ha_innobase::create (this=<optimized out>, name=0x400 <Address 0x400 out of bounds>, form=0x7fc3f082
#20 0x00000000005c0bae in ha_create_table (thd=0x2a10d50, path=<optimized out>, db=0x7fc2e80053f8 "test", table_name=
#21 0x00000000007d8766 in rea_create_table (thd=0x2a10d50, path=0x7fc3f0825e40 "./test/e", db=0x7fc2e80053f8 "test", table_name=
#22 0x000000000077c159 in create_table_impl (thd=0x2a10d50, db=0x7fc2e80053f8 "test", table_name=
#23 0x000000000077cb57 in mysql_create_
#24 0x0000000000702f45 in create_
#25 0x00000000007031d4 in select_
#26 0x000000000074314f in JOIN::prepare (this=0x7fc2e40
#27 0x000000000074b9fa in mysql_prepare_
#28 mysql_select (thd=0x2a10d50, tables=
#29 0x000000000074bdbb in handle_select (thd=0x2a10d50, result=
#30 0x0000000000727dd5 in mysql_execute_
#31 0x0000000000729328 in mysql_parse (thd=0x2a10d50, rawbuf=0x2a13140 "Pc9\001", length=<optimized out>, parser_
#32 0x000000000072a48c in dispatch_command (command=COM_QUERY, thd=0x2a10d50, packet=
#33 0x000000000072b687 in do_command (thd=0x2a10d50) at /bzr/5.
#34 0x00000000007d8c07 in threadpool_
#35 0x00000000007db918 in handle_event (connection=
#36 worker_main (param=0x1527e00 <all_groups+1024>) at /bzr/5.
#37 0x0000000000a2cdda in pfs_spawn_thread (arg=0x7fc2ec00
#38 0x0000003637207851 in start_thread () from /lib64/
#39 0x0000003636ee890d in clone () from /lib64/libc.so.6
It is waiting to S-latch the the btr latch part, but no other thread holds it, thus a missed wakeup event.
(gdb) print/x (*(prio_rw_lock_t *)cell- >wait_object) .base_lock- >lock_word
$17 = 0x100000 - unlocked
(gdb) print event
$14 = (os_event_t) 0x27e6c30 - equal to lock->event below
(gdb) print *(prio_rw_lock_t *)cell->wait_object latch_arr[ i]", s_file_ name = 0xe1eb90 "/bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ btr/btr0sea. cc", x_file_ name = 0xe1eb90 "/bzr/5. 6_dbg/Percona- Server- 5.6.13- rc60.6/ storage/ innobase/ btr/btr0sea. cc", writer_is_wait_ex = 0, last_s_line = 954, last_x_line = 1653, magic_n = 22643}, priority_ s_waiters = 0, high_priority_ s_event = 0x27e6d50, high_priority_ x_waiters = 0, high_priority_ x_event = 0x27e6de0, high_priority_ wait_ex_ waiter = 1}
$13 = {base_lock = {lock_word = 1048576, waiters = 1, recursive = 0, writer_thread = 140478917900032, event = 0x27e6c30, wait_ex_event = 0x27e6cc0, list = {prev = 0x27e82a0, next = 0x27d24c0},
debug_list = {count = 0, start = 0x0, end = 0x0}, level = 160, pfs_psi = 0x0, count_os_wait = 264, lock_name = 0xe1f3cf "&btr_search_
last_
last_
high_