Comment 5 for bug 1441139

I am also seeing various other sporadic bugs when

SET GLOBAL scalability_metrics_control = OFF;
SET GLOBAL scalability_metrics_control = ON;

is used, perhaps in combination with other SQL.

An example stack;

+bt
#0 0x00007f007410e741 in __pthread_kill (threadid=<optimized out>, signo=11) at ../nptl/sysdeps/unix/sysv/linux/pthread_kill.c:61
#1 0x0000000000abf206 in my_write_core (sig=11) at /git/PS-5.6.30_dbg/mysys/stacktrace.c:422
#2 0x0000000000735c63 in handle_fatal_signal (sig=11) at /git/PS-5.6.30_dbg/sql/signal_handler.cc:236
#3 <signal handler called>
#4 0x0000000000e6acd6 in my_lfind (head=0x7efffc031ce8, cs=0x1501e20 <my_charset_bin>, hashnr=66676499, key=0x7f0043665170 " \353Z\203\251l\306\021\223\\\332A\214\202\345\062test", keylen=212, cursor=0x7f00436650d0, pins=0x7efffc01e440) at /git/PS-5.6.30_dbg/mysys/lf_hash.c:95
#5 0x0000000000e6b154 in my_lsearch (head=0x7efffc031ce8, cs=0x1501e20 <my_charset_bin>, hashnr=66676499, key=0x7f0043665170 " \353Z\203\251l\306\021\223\\\332A\214\202\345\062test", keylen=212, pins=0x7efffc01e440) at /git/PS-5.6.30_dbg/mysys/lf_hash.c:267
#6 0x0000000000e6b82d in lf_hash_search (hash=0x17ee180 <digest_hash>, pins=0x7efffc01e440, key=0x7f0043665170, keylen=212) at /git/PS-5.6.30_dbg/mysys/lf_hash.c:462
#7 0x0000000000adf05e in find_or_create_digest (thread=0x7f005d732e40, digest_storage=0x2106e50, schema_name=0x2106f38 "test", schema_name_length=4) at /git/PS-5.6.30_dbg/storage/perfschema/pfs_digest.cc:223
#8 0x0000000000b14954 in end_statement_v1 (locker=0x2106e90, stmt_da=0x2108678) at /git/PS-5.6.30_dbg/storage/perfschema/pfs.cc:4815
#9 0x00000000007e2ad8 in inline_mysql_end_statement (locker=0x2106e90, stmt_da=0x2108678) at /git/PS-5.6.30_dbg/include/mysql/psi/mysql_statement.h:215
#10 0x00000000007e788b in dispatch_command (command=COM_QUERY, thd=0x2105200, packet=0x2227be1 "", packet_length=73) at /git/PS-5.6.30_dbg/sql/sql_parse.cc:1893
#11 0x00000000007e519f in do_command (thd=0x2105200) at /git/PS-5.6.30_dbg/sql/sql_parse.cc:1053
#12 0x00000000007ac701 in do_handle_one_connection (thd_arg=0x2105200) at /git/PS-5.6.30_dbg/sql/sql_connect.cc:1541
#13 0x00000000007ac181 in handle_one_connection (arg=0x2105200) at /git/PS-5.6.30_dbg/sql/sql_connect.cc:1444
#14 0x0000000000b0e4c9 in pfs_spawn_thread (arg=0x21021c0) at /git/PS-5.6.30_dbg/storage/perfschema/pfs.cc:1860
#15 0x00007f0074109dc5 in start_thread (arg=0x7f0043666700) at pthread_create.c:308
#16 0x00007f007256821d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113