Samples: 695K of event 'cycles', 4000 Hz, Event count (approx.): 29404455752 lost: 0/0 drop: 0/0
Overhead  Shared Object        Symbol
  22.92%  mysqld               [.] log_writer
   4.86%  mysqld               [.] log_advance_ready_for_write_lsn
   4.20%  [kernel]             [k] do_syscall_64
   2.11%  mysqld               [.] ut_delay
   1.98%  [kernel]             [k] syscall_return_via_sysret
   1.93%  [kernel]             [k] entry_SYSCALL_64
   1.67%  libpthread-2.27.so   [.] __pthread_mutex_lock
   0.96%  libpthread-2.27.so   [.] __pthread_mutex_cond_lock
   0.91%  [kernel]             [k] psi_task_change
   0.63%  [kernel]             [k] copy_user_enhanced_fast_string
   0.58%  [kernel]             [k] start_this_handle
   0.51%  [kernel]             [k] xas_load
   0.50%  [kernel]             [k] _raw_spin_lock_irqsave
   0.48%  [kernel]             [k] __fget
   0.48%  mysqld               [.] Fil_shard::do_redo_io
   0.48%  mysqld               [.] PolicyMutex<TTASEventMutex<GenericPolicy> >::exit
   0.47%  [kernel]             [k] ext4_da_write_begin
   0.46%  [kernel]             [k] jbd2_journal_stop
   0.46%  mysqld               [.] mtr_t::Command::add_dirty_blocks_to_flush_list
   0.43%  mysqld               [.] log_update_buf_limit
   0.43%  mysqld               [.] LinuxAIOHandler::find_completed_slot
   0.43%  mysqld               [.] PolicyMutex<TTASEventMutex<GenericPolicy> >::enter
   0.42%  mysqld               [.] Buf_fetch<Buf_fetch_normal>::single_page
   0.41%  mysqld               [.] TrxUndoRsegsIterator::set_next
   0.39%  [kernel]             [k] iov_iter_fault_in_readable
   0.39%  [kernel]             [k] kmem_cache_alloc
   0.39%  [kernel]             [k] _raw_spin_lock
   0.36%  libpthread-2.27.so   [.] __pthread_mutex_unlock
   0.36%  mysqld               [.] log_files_real_offset_for_lsn
   0.36%  [kernel]             [k] common_file_perm
   0.36%  [kernel]             [k] ext4_file_write_iter
   0.35%  libpthread-2.27.so   [.] __libc_pwrite64
   0.34%  mysqld               [.] 0x00000000024d59e1
   0.34%  [kernel]             [k] __block_commit_write.isra.41
   0.33%  [kernel]             [k] _raw_read_lock
   0.33%  mysqld               [.] mlog_write_ulint
   0.33%  [kernel]             [k] __audit_syscall_exit
   0.31%  [kernel]             [k] ext4_da_write_end
   0.31%  [kernel]             [k] visit_groups_merge
   0.30%  [kernel]             [k] native_queued_spin_lock_slowpath
   0.30%  mysqld               [.] buf_page_get_gen
   0.30%  [kernel]             [k] find_get_entry
   0.29%  [kernel]             [k] kmem_cache_free
   0.29%  [kernel]             [k] add_transaction_credits
   0.28%  mysqld               [.] Adaptive_flush::set_flush_target_by_lsn
   0.27%  mysqld               [.] 0x000000000261dad0
   0.26%  [kernel]             [k] update_load_avg
   0.26%  libc-2.27.so         [.] malloc
   0.25%  mysqld               [.] Fil_shard::get_space_by_id
   0.24%  mysqld               [.] log_buffer_reserve
   0.24%  [kernel]             [k] switch_fpu_return
   0.24%  [kernel]             [k] unlock_page
   0.24%  [kernel]             [k] generic_perform_write
   0.23%  mysqld               [.] 0x000000000261db60
   0.23%  [kernel]             [k] ext4_block_write_begin
   0.23%  mysqld               [.] 0x000000000261db20
   0.23%  libc-2.27.so         [.] 0x000000000018ec34
For a higher level overview, try: perf top --sort comm,dso