Samples: 28M of event 'cycles', 4000 Hz, Event count (approx.): 66509855317 lost: 0/0 drop: 0/0
Overhead  Shared Object        Symbol
  21.27%  mysqld               [.] log_writer
   6.06%  mysqld               [.] ut_delay
   4.35%  [kernel]             [k] do_syscall_64
   4.32%  mysqld               [.] log_advance_ready_for_write_lsn
   2.05%  [kernel]             [k] syscall_return_via_sysret
   1.97%  [kernel]             [k] entry_SYSCALL_64
   1.30%  [kernel]             [k] psi_task_change
   1.02%  libpthread-2.27.so   [.] __pthread_mutex_lock
   0.89%  mysqld               [.] LinuxAIOHandler::find_completed_slot
   0.60%  [kernel]             [k] _raw_spin_lock_irqsave
   0.56%  [kernel]             [k] _raw_spin_lock
   0.55%  [kernel]             [k] copy_user_enhanced_fast_string
   0.54%  [kernel]             [k] start_this_handle
   0.48%  libpthread-2.27.so   [.] __pthread_mutex_unlock
   0.48%  [kernel]             [k] ext4_es_lookup_extent
   0.46%  [kernel]             [k] __fget
   0.43%  [kernel]             [k] gup_pgd_range
   0.43%  mysqld               [.] page_simple_validate_new
   0.43%  [kernel]             [k] ext4_da_write_begin
   0.43%  mysqld               [.] TrxUndoRsegsIterator::set_next
   0.43%  [kernel]             [k] xas_load
   0.42%  [kernel]             [k] jbd2_journal_stop
   0.41%  mysqld               [.] 0x000000000261db20
   0.40%  [kernel]             [k] switch_fpu_return
   0.40%  mysqld               [.] log_update_buf_limit
   0.40%  [kernel]             [k] __audit_syscall_exit
   0.39%  mysqld               [.] PolicyMutex<TTASEventMutex<GenericPolicy> >::exit
   0.39%  mysqld               [.] Fil_shard::do_redo_io
   0.38%  [kernel]             [k] kmem_cache_alloc
   0.38%  mysqld               [.] PolicyMutex<TTASEventMutex<GenericPolicy> >::enter
   0.35%  libc-2.27.so         [.] 0x000000000018ee6d
   0.35%  [kernel]             [k] do_blockdev_direct_IO
   0.34%  [kernel]             [k] native_write_msr
   0.34%  mysqld               [.] Buf_fetch<Buf_fetch_normal>::single_page
   0.34%  mysqld               [.] mtr_t::Command::add_dirty_blocks_to_flush_list
   0.34%  [kernel]             [k] __schedule
   0.33%  [kernel]             [k] update_load_avg
   0.31%  [kernel]             [k] ext4_file_write_iter
   0.31%  [kernel]             [k] common_file_perm
   0.31%  [kernel]             [k] _raw_read_lock
   0.30%  [kernel]             [k] kmem_cache_free
   0.30%  [kernel]             [k] native_queued_spin_lock_slowpath
   0.29%  [kernel]             [k] iov_iter_fault_in_readable
   0.29%  mysqld               [.] log_files_real_offset_for_lsn
   0.29%  [kernel]             [k] native_sched_clock
   0.29%  [kernel]             [k] update_curr
   0.29%  mysqld               [.] que_run_threads
   0.28%  mysqld               [.] Adaptive_flush::set_flush_target_by_lsn
   0.27%  [kernel]             [k] perf_event_update_userpage
   0.27%  [kernel]             [k] record_times
   0.27%  mysqld               [.] 0x00000000024d59e1
   0.27%  [kernel]             [k] add_transaction_credits
   0.27%  [kernel]             [k] __block_commit_write.isra.41
   0.27%  libpthread-2.27.so   [.] __libc_pwrite64
   0.26%  mysqld               [.] 0x000000000261dae8
   0.26%  mysqld               [.] 0x000000000261dad0
   0.25%  [kernel]             [k] __lock_text_start
For a higher level overview, try: perf top --sort comm,dso