10.6.8 (+uring compiled in but not used) hangs after sudden load spikes

# ldd /opt/wmf-mariadb106/bin/mysqld | grep uring

	liburing.so.1 => /lib/x86_64-linux-gnu/liburing.so.1 (0x00007f4d12123000)

root@db1132:/srv/tmp# gdb /opt/wmf-mariadb106/bin/mysqld core.3344701

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Reading symbols from /opt/wmf-mariadb106/bin/mysqld...

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[Thread debugging using libthread_db enabled]

Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

--Type <RET> for more, q to quit, c to continue without paging--c

Core was generated by `/opt/wmf-mariadb106/bin/mysqld'.

#0  0x00007fac896ec3ff in poll () from /lib/x86_64-linux-gnu/libc.so.6

[Current thread is 1 (Thread 0x7fac893631c0 (LWP 3344701))]

(gdb) thread 11

[Switching to thread 11 (Thread 0x7fac808e3700 (LWP 3344713))]

#0  0x00007fac896f19b9 in syscall () from /lib/x86_64-linux-gnu/libc.so.6

(gdb) frame 6

#6  btr_cur_search_to_nth_level_func (index=index@entry=0x7f4c5406d500, level=level@entry=0, tuple=tuple@entry=0x7f49a9189ab0, mode=mode@entry=PAGE_CUR_LE, latch_mode=<optimized out>, latch_mode@entry=33, cursor=cursor@entry=0x7fac808e05f0, ahi_latch=<optimized out>,

    mtr=<optimized out>, autoinc=<optimized out>) at /root/mariadb-10.6.8/storage/innobase/btr/btr0cur.cc:2229

2229	/root/mariadb-10.6.8/storage/innobase/btr/btr0cur.cc: No such file or directory.

(gdb) p *index

$1 = {static MAX_N_FIELDS = 1023, id = 6376, heap = 0x7f4c5405a008, name = {m_name = 0x7f4c5406d690 "PRIMARY"}, table = 0x7f4c54059c90, page = 3, merge_threshold = 50, type = 3, trx_id_offset = 0, n_user_defined_cols = 2, nulls_equal = 0, n_uniq = 2, n_def = 5,

  n_fields = 5, n_nullable = 1, n_core_fields = 5, n_core_null_bytes = 1, static NO_CORE_NULL_BYTES = 255, static DICT_INDEXES_ID = 3, cached = 1, to_be_dropped = 0, online_status = 0, uncommitted = 0, fields = 0x7f4c5406d730, parser = 0x0, new_vcol_info = 0x0,

  indexes = {prev = 0x0, next = 0x7f4c5406dcc0}, search_info = 0x7f4c5406d828, online_log = 0x0, stat_n_diff_key_vals = 0x7f4c5406d7f8, stat_n_sample_sizes = 0x7f4c5406d808, stat_n_non_null_key_vals = 0x7f4c5406d818, stat_index_size = 1320173,

  stat_n_leaf_pages = 1151220, stats_error_printed = false, stat_defrag_modified_counter = 8582, stat_defrag_n_pages_freed = 0, stat_defrag_n_page_split = 8582, stat_defrag_data_size_sample = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, stat_defrag_sample_next_slot = 0, rtr_ssn = {

    m = {<std::__atomic_base<unsigned int>> = {static _S_alignment = 4, _M_i = 0}, <No data fields>}}, rtr_track = 0x0, trx_id = 0, zip_pad = {mutex = {<std::__mutex_base> = {_M_mutex = {__data = {__lock = 0, __count = 0, __owner = 0, __nusers = 0, __kind = 0,

            __spins = 0, __elision = 0, __list = {__prev = 0x0, __next = 0x0}}, __size = '\000' <repeats 39 times>, __align = 0}}, <No data fields>}, pad = {m = {<std::__atomic_base<unsigned long>> = {static _S_alignment = 8, _M_i = 1408}, <No data fields>}},

    success = 125, failure = 0, n_rounds = 0}, lock = {lock = {pfs_psi = 0x7fac835f9b40, lock = {writer = {lock = {<std::__atomic_base<unsigned int>> = {static _S_alignment = 4, _M_i = 2147483649}, <No data fields>}, static HOLDER = 2147483648},

        readers = {<std::__atomic_base<unsigned int>> = {static _S_alignment = 4, _M_i = 213}, <No data fields>}, static WRITER = 2147483648}}, recursive = 65536, writer = {<std::__atomic_base<unsigned long>> = {static _S_alignment = 8,

        _M_i = 140378867906304}, <No data fields>}, static FOR_IO = <optimized out>, static RECURSIVE_X = 1, static RECURSIVE_U = 65536, static RECURSIVE_MAX = <optimized out>}}

(gdb)

(gdb) thread 11

[Switching to thread 11 (Thread 0x7fac808e3700 (LWP 3344713))]

#0  0x00007fac896f19b9 in syscall () from /lib/x86_64-linux-gnu/libc.so.6

(gdb) frame 6

#6  btr_cur_search_to_nth_level_func (index=index@entry=0x7f4c5406d500, level=level@entry=0, tuple=tuple@entry=0x7f49a9189ab0, mode=mode@entry=PAGE_CUR_LE, latch_mode=<optimized out>, latch_mode@entry=33, cursor=cursor@entry=0x7fac808e05f0, ahi_latch=<optimized out>,

    mtr=<optimized out>, autoinc=<optimized out>) at /root/mariadb-10.6.8/storage/innobase/btr/btr0cur.cc:2229

2229	/root/mariadb-10.6.8/storage/innobase/btr/btr0cur.cc: No such file or directory.

(gdb) p index->table->space->chain.start->name

$1 = 0x564d2408d618 "./enwiki/user_properties.ibd"

(gdb) thread 11

[Switching to thread 11 (Thread 0x7fac808e3700 (LWP 3344713))]

#0  0x00007fac896f19b9 in syscall () from /lib/x86_64-linux-gnu/libc.so.6

(gdb) frame 6

#6  btr_cur_search_to_nth_level_func (index=index@entry=0x7f4c5406d500, level=level@entry=0, tuple=tuple@entry=0x7f49a9189ab0, mode=mode@entry=PAGE_CUR_LE, latch_mode=<optimized out>, latch_mode@entry=33, cursor=cursor@entry=0x7fac808e05f0, ahi_latch=<optimized out>,

    mtr=<optimized out>, autoinc=<optimized out>) at /root/mariadb-10.6.8/storage/innobase/btr/btr0cur.cc:2229

2229	/root/mariadb-10.6.8/storage/innobase/btr/btr0cur.cc: No such file or directory.

(gdb) p index->table->space->chain.start->handle

$1 = {m_file = 133, m_psi = 0x7fac8302afc0}