| Demonstrations of offwaketime, the Linux eBPF/bcc version. |
| |
| |
| This program shows kernel stack traces and task names that were blocked and |
| "off-CPU", along with the stack traces and task names for the threads that woke |
| them, and the total elapsed time from when they blocked to when they were woken |
| up. This combines the summaries from both the offcputime and wakeuptime tools. |
| The time measurement will be very similar to off-CPU time, however, off-CPU time |
| may include a little extra time spent waiting on a run queue to be scheduled. |
| The combined stacks, task names, and total time is summarized in kernel context |
| for efficiency, using an eBPF map. |
| |
| The output summary will further help you identify reasons why threads |
| were blocking, and quantify the time from when they were blocked to woken up. |
| This spans all types of blocking activity: disk I/O, network I/O, locks, page |
| faults, swapping, sleeping, involuntary context switches, etc. |
| |
| Here is some sample output from a 5 second trace, truncated to highlight several |
| stack pairs: |
| |
| # ./offwaketime 5 |
| Tracing blocked time (us) by kernel off-CPU and waker stack for 5 secs. |
| |
| [...] |
| |
| waker: swapper/0 |
| ffffffff8137897c blk_mq_complete_request |
| ffffffff81378930 __blk_mq_complete_request |
| ffffffff81378793 blk_mq_end_request |
| ffffffff813778b9 blk_mq_free_request |
| ffffffff8137782d __blk_mq_free_request |
| ffffffff8137bc57 blk_mq_put_tag |
| ffffffff8137b2c7 bt_clear_tag |
| ffffffff810b54d9 __wake_up |
| ffffffff810b5462 __wake_up_common |
| ffffffff810b5b12 autoremove_wake_function |
| - - |
| ffffffff81785085 schedule |
| ffffffff81787e16 schedule_timeout |
| ffffffff81784634 __sched_text_start |
| ffffffff8137b839 bt_get |
| ffffffff8137bbf7 blk_mq_get_tag |
| ffffffff8137761b __blk_mq_alloc_request |
| ffffffff81379442 blk_mq_map_request |
| ffffffff8137a445 blk_sq_make_request |
| ffffffff8136ebc3 generic_make_request |
| ffffffff8136ed07 submit_bio |
| ffffffff81225adf submit_bh_wbc |
| ffffffff81225b42 submit_bh |
| ffffffff812721e0 __ext4_get_inode_loc |
| ffffffff812751dd ext4_iget |
| ffffffff81275c90 ext4_iget_normal |
| ffffffff8127f45b ext4_lookup |
| ffffffff811f94ed lookup_real |
| ffffffff811fad43 __lookup_hash |
| ffffffff811fc3fb walk_component |
| ffffffff811fd050 link_path_walk |
| target: cksum |
| 56529 |
| |
| [...] |
| |
| waker: swapper/1 |
| ffffffff81475cf0 xen_evtchn_do_upcall |
| ffffffff81473e83 __xen_evtchn_do_upcall |
| ffffffff814766f7 evtchn_2l_handle_events |
| ffffffff810cb0c2 generic_handle_irq |
| ffffffff810cf1ca handle_percpu_irq |
| ffffffff810cb9c8 handle_irq_event_percpu |
| ffffffff8100b9e1 xen_timer_interrupt |
| ffffffff810dfba8 hrtimer_interrupt |
| ffffffff810df494 __hrtimer_run_queues |
| ffffffff810df082 hrtimer_wakeup |
| - - |
| ffffffff81785085 schedule |
| ffffffff817880bf do_nanosleep |
| ffffffff810e003d hrtimer_nanosleep |
| ffffffff810e018c sys_nanosleep |
| ffffffff81789076 entry_SYSCALL_64_fastpath |
| target: vmstat |
| 3000331 |
| |
| [...] |
| |
| waker: swapper/0 |
| ffffffff81378930 __blk_mq_complete_request |
| ffffffff8137875a blk_mq_end_request |
| ffffffff8136f157 blk_update_request |
| ffffffff8136836f bio_endio |
| ffffffff812ba709 mpage_end_io |
| ffffffff81176af9 unlock_page |
| ffffffff810b5781 __wake_up_bit |
| ffffffff810b54d9 __wake_up |
| ffffffff810b5462 __wake_up_common |
| ffffffff810b5b7e wake_bit_function |
| - - |
| ffffffff81785085 schedule |
| ffffffff81787e16 schedule_timeout |
| ffffffff81784634 __sched_text_start |
| ffffffff8178586b bit_wait_io |
| ffffffff8178563e __wait_on_bit_lock |
| ffffffff8117616e __lock_page_killable |
| ffffffff81177fce generic_file_read_iter |
| ffffffff811ef9c7 __vfs_read |
| ffffffff811f0206 vfs_read |
| ffffffff811f0eb6 sys_read |
| ffffffff81789076 entry_SYSCALL_64_fastpath |
| target: cksum |
| 4334521 |
| |
| [...] |
| |
| waker: kworker/u16:2 |
| ffffffff8178940f ret_from_fork |
| ffffffff81092979 kthread |
| ffffffff8108caeb worker_thread |
| ffffffff8108c80a process_one_work |
| ffffffff81496df5 flush_to_ldisc |
| ffffffff81494424 n_tty_receive_buf2 |
| ffffffff814939fd n_tty_receive_buf_common |
| ffffffff810b54d9 __wake_up |
| ffffffff810b5462 __wake_up_common |
| ffffffff812037b6 pollwake |
| - - |
| ffffffff81785085 schedule |
| ffffffff81788234 schedule_hrtimeout_range_clock |
| ffffffff81788253 schedule_hrtimeout_range |
| ffffffff812035d4 poll_schedule_timeout |
| ffffffff8120402a do_select |
| ffffffff812042f0 core_sys_select |
| ffffffff8120449b sys_select |
| ffffffff81789076 entry_SYSCALL_64_fastpath |
| target: sshd |
| 6530897 |
| |
| [...] |
| |
| waker: swapper/0 |
| ffffffff81475cf0 xen_evtchn_do_upcall |
| ffffffff81473e83 __xen_evtchn_do_upcall |
| ffffffff814766f7 evtchn_2l_handle_events |
| ffffffff810cb0c2 generic_handle_irq |
| ffffffff810cf1ca handle_percpu_irq |
| ffffffff810cb9c8 handle_irq_event_percpu |
| ffffffff8100b9e1 xen_timer_interrupt |
| ffffffff810dfba8 hrtimer_interrupt |
| ffffffff810df494 __hrtimer_run_queues |
| ffffffff810df082 hrtimer_wakeup |
| - - |
| ffffffff81785085 schedule |
| ffffffff81787fc3 schedule_hrtimeout_range_clock.part.23 |
| ffffffff81788219 schedule_hrtimeout_range_clock |
| ffffffff81788253 schedule_hrtimeout_range |
| ffffffff812035d4 poll_schedule_timeout |
| ffffffff81204b6d do_sys_poll |
| ffffffff81204cf2 sys_poll |
| ffffffff81789076 entry_SYSCALL_64_fastpath |
| target: supervise |
| 16332240 |
| |
| Detaching... |
| |
| The output includes two paths from the cksum(1) command, one for reading files |
| via vfs_read() and the other doing a link_path_walk(). There is also a vmstat(8) |
| stack showing it sleeping between intervals, and an sshd(8) stack showing it |
| waiting on a file descriptor for input. |
| |
| The stack shown at the bottom is the off-CPU stack belonging to the task name |
| shown after "target:". Then there is a separator, "-", and above it the waker |
| stack and the waker task name after "waker:". The wakeup stack is printed |
| in reverse order. |
| |
| The number beneath the stacks is the total time spent from the blocking event |
| to the wakeup event. This is summed for all occurances with the same stack |
| pairs. |
| |
| |
| The -u option will print user-mode target threads only, and the -f option will |
| show the stacks in "folded stacks" format. Eg: |
| |
| # ./offwaketime -fu 5 |
| supervise;entry_SYSCALL_64_fastpath;sys_rename;dput;__dentry_kill;iput;evict;ext4_evict_inode;ext4_truncate;ext4_ext_truncate;ext4_ext_remove_space;ext4_free_blocks;__ext4_handle_dirty_metadata;_cond_resched;preempt_schedule_common;-; 2 |
| sshd;entry_SYSCALL_64_fastpath;sys_read;vfs_read;__vfs_read;tty_read;n_tty_read;down_read;_cond_resched;preempt_schedule_common;-; 2 |
| cksum;entry_SYSCALL_64_fastpath;sys_open;do_sys_open;do_filp_open;path_openat;lookup_real;ext4_lookup;ext4_iget_normal;ext4_iget;iget_locked;alloc_inode;ext4_alloc_inode;kmem_cache_alloc;_cond_resched;preempt_schedule_common;-; 3 |
| mkdir;page_fault;do_page_fault;__do_page_fault;handle_mm_fault;anon_vma_prepare;_cond_resched;preempt_schedule_common;-; 3 |
| cksum;entry_SYSCALL_64_fastpath;sys_open;do_sys_open;do_filp_open;path_openat;link_path_walk;walk_component;__lookup_hash;lookup_real;ext4_lookup;ext4_iget_normal;ext4_iget;__ext4_get_inode_loc;__breadahead;ll_rw_block;submit_bh_wbc;bio_alloc_bioset;mempool_alloc;_cond_resched;preempt_schedule_common;-; 3 |
| cksum;entry_SYSCALL_64_fastpath;sys_read;vfs_read;__vfs_read;generic_file_read_iter;page_cache_sync_readahead;ondemand_readahead;__do_page_cache_readahead;ext4_readpages;ext4_mpage_readpages;ext4_map_blocks;down_read;_cond_resched;preempt_schedule_common;-; 3 |
| cksum;entry_SYSCALL_64_fastpath;sys_open;do_sys_open;fd_install;__fd_install;_cond_resched;preempt_schedule_common;-; 3 |
| run;return_from_execve;sys_execve;do_execveat_common.isra.33;search_binary_handler;load_script;search_binary_handler;load_elf_binary;elf_map;vm_munmap;down_write;_cond_resched;preempt_schedule_common;-; 3 |
| svscan;entry_SYSCALL_64_fastpath;sys_getdents;iterate_dir;ext4_readdir;ext4_htree_fill_tree;htree_dirblock_to_tree;ext4_htree_store_dirent;__kmalloc;_cond_resched;preempt_schedule_common;-; 4 |
| cksum;entry_SYSCALL_64_fastpath;sys_open;do_sys_open;do_filp_open;path_openat;mutex_lock;_cond_resched;preempt_schedule_common;-; 4 |
| run;entry_SYSCALL_64_fastpath;sys_mprotect;down_write;_cond_resched;preempt_schedule_common;-; 5 |
| sshd;entry_SYSCALL_64_fastpath;sys_select;core_sys_select;do_select;_cond_resched;preempt_schedule_common;-; 5 |
| run;return_from_execve;sys_execve;do_execveat_common.isra.33;search_binary_handler;load_script;search_binary_handler;load_elf_binary;set_brk;vm_brk;down_write;_cond_resched;preempt_schedule_common;-; 5 |
| supervise;entry_SYSCALL_64_fastpath;sys_clone;_do_fork;copy_process;anon_vma_fork;anon_vma_clone;down_write;_cond_resched;preempt_schedule_common;-; 6 |
| svscan;retint_user;prepare_exit_to_usermode;exit_to_usermode_loop;schedule;-;hrtimer_wakeup;__hrtimer_run_queues;hrtimer_interrupt;xen_timer_interrupt;handle_irq_event_percpu;handle_percpu_irq;generic_handle_irq;evtchn_2l_handle_events;__xen_evtchn_do_upcall;xen_evtchn_do_upcall;swapper/0 11 |
| supervise;return_from_execve;sys_execve;do_execveat_common.isra.33;search_binary_handler;load_script;search_binary_handler;load_elf_binary;flush_old_exec;mmput;exit_mmap;free_pgtables;unlink_anon_vmas;down_write;_cond_resched;preempt_schedule_common;-; 12 |
| run;return_from_execve;sys_execve;do_execveat_common.isra.33;search_binary_handler;load_elf_binary;flush_old_exec;mmput;_cond_resched;preempt_schedule_common;-; 13 |
| sshd;entry_SYSCALL_64_fastpath;sys_write;vfs_write;__vfs_write;sock_write_iter;sock_sendmsg;inet_sendmsg;tcp_sendmsg;lock_sock_nested;_cond_resched;preempt_schedule_common;-; 14 |
| cksum;entry_SYSCALL_64_fastpath;sys_write;vfs_write;__vfs_write;tty_write;n_tty_write;mutex_lock;_cond_resched;preempt_schedule_common;-; 19 |
| sshd;retint_user;prepare_exit_to_usermode;exit_to_usermode_loop;schedule;-; 24 |
| run;return_from_execve;sys_execve;do_execveat_common.isra.33;search_binary_handler;load_script;search_binary_handler;load_elf_binary;vm_brk;down_write;_cond_resched;preempt_schedule_common;-; 31 |
| sshd;entry_SYSCALL_64_fastpath;sys_write;vfs_write;__vfs_write;sock_write_iter;sock_sendmsg;inet_sendmsg;tcp_sendmsg;sk_stream_alloc_skb;__alloc_skb;kmem_cache_alloc_node;_cond_resched;preempt_schedule_common;-; 32 |
| run;page_fault;do_page_fault;__do_page_fault;_cond_resched;preempt_schedule_common;-; 33 |
| run;page_fault;do_page_fault;__do_page_fault;handle_mm_fault;anon_vma_prepare;_cond_resched;preempt_schedule_common;-; 33 |
| run;entry_SYSCALL_64_fastpath;sys_clone;_do_fork;copy_process;down_write;_cond_resched;preempt_schedule_common;-; 35 |
| run;page_fault;do_page_fault;__do_page_fault;handle_mm_fault;__do_fault;filemap_fault;_cond_resched;preempt_schedule_common;-; 36 |
| run;return_from_execve;sys_execve;do_execveat_common.isra.33;search_binary_handler;load_script;search_binary_handler;load_elf_binary;elf_map;vm_mmap;vm_mmap_pgoff;down_write;_cond_resched;preempt_schedule_common;-; 38 |
| cksum;entry_SYSCALL_64_fastpath;sys_open;do_sys_open;do_filp_open;path_openat;lookup_real;ext4_lookup;ext4_iget_normal;ext4_iget;__ext4_get_inode_loc;__getblk_gfp;_cond_resched;preempt_schedule_common;-; 38 |
| chmod;int_ret_from_sys_call;syscall_return_slowpath;exit_to_usermode_loop;schedule;-; 39 |
| run;entry_SYSCALL_64_fastpath;sys_munmap;vm_munmap;do_munmap;unmap_region;unmap_vmas;unmap_single_vma;_cond_resched;preempt_schedule_common;-; 41 |
| readproctitle;entry_SYSCALL_64_fastpath;sys_read;vfs_read;__vfs_read;pipe_read;mutex_lock;_cond_resched;preempt_schedule_common;-; 44 |
| run;entry_SYSCALL_64_fastpath;sys_clone;_do_fork;copy_process;kmem_cache_alloc;_cond_resched;preempt_schedule_common;-; 48 |
| run;return_from_execve;sys_execve;do_execveat_common.isra.33;search_binary_handler;load_elf_binary;flush_old_exec;mmput;exit_mmap;unmap_vmas;unmap_single_vma;_cond_resched;preempt_schedule_common;-; 49 |
| sshd;entry_SYSCALL_64_fastpath;sys_select;core_sys_select;do_select;tty_poll;tty_ldisc_ref_wait;ldsem_down_read;_cond_resched;preempt_schedule_common;-; 50 |
| supervise;return_from_execve;sys_execve;do_execveat_common.isra.33;search_binary_handler;load_script;remove_arg_zero;get_user_pages;__get_user_pages;_cond_resched;preempt_schedule_common;-; 50 |
| readproctitle;int_ret_from_sys_call;syscall_return_slowpath;exit_to_usermode_loop;schedule;-; 51 |
| mkdir;int_ret_from_sys_call;syscall_return_slowpath;exit_to_usermode_loop;schedule;-; 53 |
| supervise;entry_SYSCALL_64_fastpath;sys_clone;_do_fork;copy_process;copy_creds;prepare_creds;kmem_cache_alloc;_cond_resched;preempt_schedule_common;-; 66 |
| cksum;entry_SYSCALL_64_fastpath;sys_open;do_sys_open;do_filp_open;path_openat;lookup_real;ext4_lookup;ext4_find_entry;__ext4_read_dirblock;ext4_bread;ext4_getblk;__getblk_gfp;_cond_resched;preempt_schedule_common;-; 76 |
| run;return_from_execve;sys_execve;do_execveat_common.isra.33;search_binary_handler;load_elf_binary;kernel_read;vfs_read;__vfs_read;generic_file_read_iter;_cond_resched;preempt_schedule_common;-; 96 |
| chmod;entry_SYSCALL_64_fastpath;sys_exit_group;do_group_exit;do_exit;mmput;exit_mmap;unmap_vmas;unmap_single_vma;_cond_resched;preempt_schedule_common;-; 100 |
| run;page_fault;do_page_fault;__do_page_fault;handle_mm_fault;__do_fault;filemap_fault;__lock_page_or_retry;wait_on_page_bit_killable;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;unlock_page;handle_mm_fault;__do_page_fault;do_page_fault;page_fault;;run 117 |
| run;entry_SYSCALL_64_fastpath;sys_clone;_do_fork;copy_process;copy_page_range;_cond_resched;preempt_schedule_common;-; 117 |
| cksum;entry_SYSCALL_64_fastpath;sys_read;vfs_read;__vfs_read;generic_file_read_iter;_cond_resched;preempt_schedule_common;-; 121 |
| chown;entry_SYSCALL_64_fastpath;sys_mmap;sys_mmap_pgoff;vm_mmap_pgoff;down_write;_cond_resched;preempt_schedule_common;-; 137 |
| chown;entry_SYSCALL_64_fastpath;sys_mmap;sys_mmap_pgoff;vm_mmap_pgoff;do_mmap;mmap_region;kmem_cache_alloc;_cond_resched;preempt_schedule_common;-; 138 |
| run;return_from_execve;sys_execve;do_execveat_common.isra.33;count.isra.21.constprop.38;_cond_resched;preempt_schedule_common;-; 145 |
| supervise;entry_SYSCALL_64_fastpath;sys_rename;dput;__dentry_kill;iput;evict;ext4_evict_inode;truncate_inode_pages_final;truncate_inode_pages_range;wait_on_page_bit;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;end_page_writeback;ext4_finish_bio;ext4_end_bio;bio_endio;blk_update_request;blk_mq_end_request;mkdir 147 |
| chmod;return_from_execve;sys_execve;do_execveat_common.isra.33;search_binary_handler;load_elf_binary;clear_user;page_fault;do_page_fault;__do_page_fault;_cond_resched;preempt_schedule_common;-; 159 |
| chown;return_from_execve;sys_execve;do_execveat_common.isra.33;search_binary_handler;load_elf_binary;setup_arg_pages;shift_arg_pages;vma_adjust;down_write;_cond_resched;preempt_schedule_common;-; 173 |
| chown;retint_user;prepare_exit_to_usermode;exit_to_usermode_loop;schedule;-; 176 |
| chmod;retint_user;prepare_exit_to_usermode;exit_to_usermode_loop;schedule;-; 191 |
| chmod;entry_SYSCALL_64_fastpath;sys_fchmodat;chmod_common;notify_change;ext4_setattr;__mark_inode_dirty;ext4_dirty_inode;ext4_mark_inode_dirty;ext4_reserve_inode_write;__ext4_get_inode_loc;__getblk_gfp;_cond_resched;preempt_schedule_common;-; 221 |
| cksum;entry_SYSCALL_64_fastpath;sys_open;do_sys_open;do_filp_open;path_openat;trailing_symlink;page_follow_link_light;page_getlink.isra.34.constprop.38;read_cache_page;do_read_cache_page;wait_on_page_read;wait_on_page_bit;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;unlock_page;mpage_end_io;bio_endio;blk_update_request;blk_mq_end_request;__blk_mq_complete_request;swapper/0 230 |
| cksum;entry_SYSCALL_64_fastpath;sys_open;do_sys_open;do_filp_open;path_openat;lookup_real;ext4_lookup;ext4_find_entry;__ext4_read_dirblock;ext4_bread;__wait_on_buffer;out_of_line_wait_on_bit;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;wake_up_bit;unlock_buffer;__end_buffer_read_notouch;end_buffer_read_sync;end_bio_bh_io_sync;bio_endio;rcu_sched 231 |
| supervise;return_from_execve;sys_execve;do_execveat_common.isra.33;search_binary_handler;load_script;search_binary_handler;load_elf_binary;flush_old_exec;mmput;_cond_resched;preempt_schedule_common;-; 234 |
| chown;int_ret_from_sys_call;syscall_return_slowpath;exit_to_usermode_loop;schedule;-; 249 |
| cksum;entry_SYSCALL_64_fastpath;sys_read;vfs_read;__vfs_read;generic_file_read_iter;__lock_page_killable;__wait_on_bit_lock;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;unlock_page;mpage_end_io;bio_endio;blk_update_request;blk_mq_end_request;__blk_mq_complete_request;svscan 273 |
| mkdir;entry_SYSCALL_64_fastpath;sys_exit_group;do_group_exit;do_exit;mmput;exit_mmap;unmap_vmas;unmap_single_vma;_cond_resched;preempt_schedule_common;-; 382 |
| supervise;return_from_execve;sys_execve;do_execveat_common.isra.33;search_binary_handler;load_script;search_binary_handler;load_elf_binary;flush_old_exec;mmput;exit_mmap;unmap_vmas;unmap_single_vma;_cond_resched;preempt_schedule_common;-; 389 |
| run;page_fault;do_page_fault;__do_page_fault;handle_mm_fault;do_wp_page;wp_page_copy.isra.57;anon_vma_prepare;_cond_resched;preempt_schedule_common;-; 390 |
| supervise;return_from_execve;sys_execve;do_execveat_common.isra.33;sched_exec;stop_one_cpu;wait_for_completion;_cond_resched;preempt_schedule_common;-; 409 |
| run;return_from_execve;sys_execve;do_execveat_common.isra.33;sched_exec;stop_one_cpu;wait_for_completion;_cond_resched;preempt_schedule_common;-; 419 |
| mkdir;retint_user;prepare_exit_to_usermode;exit_to_usermode_loop;schedule;-; 457 |
| cksum;entry_SYSCALL_64_fastpath;sys_read;vfs_read;__vfs_read;generic_file_read_iter;__lock_page_killable;__wait_on_bit_lock;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;unlock_page;mpage_end_io;bio_endio;blk_update_request;blk_mq_end_request;__blk_mq_complete_request;rcuos/0 460 |
| run;entry_SYSCALL_64_fastpath;sys_exit_group;do_group_exit;do_exit;mmput;exit_mmap;unmap_vmas;unmap_single_vma;_cond_resched;preempt_schedule_common;-; 481 |
| sshd;int_ret_from_sys_call;syscall_return_slowpath;exit_to_usermode_loop;schedule;-; 495 |
| cksum;do_filp_open;path_openat;lookup_real;ext4_lookup;ext4_find_entry;dx_probe;__ext4_read_dirblock;ext4_bread;ext4_getblk;ext4_map_blocks;ext4_ext_map_blocks;ext4_find_extent;__read_extent_tree_block;bh_submit_read;out_of_line_wait_on_bit;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;wake_up_bit;unlock_buffer;__end_buffer_read_notouch;end_buffer_read_sync;end_bio_bh_io_sync;bio_endio;swapper/0 495 |
| cksum;entry_SYSCALL_64_fastpath;sys_open;do_sys_open;do_filp_open;path_openat;lookup_real;ext4_lookup;ext4_find_entry;dx_probe;__ext4_read_dirblock;ext4_bread;__wait_on_buffer;out_of_line_wait_on_bit;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;wake_up_bit;unlock_buffer;__end_buffer_read_notouch;end_buffer_read_sync;end_bio_bh_io_sync;bio_endio;swapper/0 514 |
| run;entry_SYSCALL_64_fastpath;sys_clone;_do_fork;copy_process;alloc_pid;kmem_cache_alloc;_cond_resched;preempt_schedule_common;-; 572 |
| run;return_from_execve;sys_execve;do_execveat_common.isra.33;search_binary_handler;load_script;search_binary_handler;load_elf_binary;clear_user;page_fault;do_page_fault;__do_page_fault;handle_mm_fault;__pte_alloc;pte_alloc_one;alloc_pages_current;__alloc_pages_nodemask;_cond_resched;preempt_schedule_common;-; 579 |
| supervise;entry_SYSCALL_64_fastpath;sys_clone;_do_fork;copy_process;copy_page_range;_cond_resched;preempt_schedule_common;-; 590 |
| cksum;int_ret_from_sys_call;syscall_return_slowpath;exit_to_usermode_loop;schedule;-; 592 |
| chmod;return_from_execve;sys_execve;do_execveat_common.isra.33;search_binary_handler;load_elf_binary;setup_arg_pages;shift_arg_pages;vma_adjust;down_write;_cond_resched;preempt_schedule_common;-; 697 |
| cksum;entry_SYSCALL_64_fastpath;sys_open;do_sys_open;do_filp_open;path_openat;lookup_real;ext4_lookup;ext4_find_entry;__ext4_read_dirblock;ext4_bread;__wait_on_buffer;out_of_line_wait_on_bit;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;wake_up_bit;unlock_buffer;__end_buffer_read_notouch;end_buffer_read_sync;end_bio_bh_io_sync;bio_endio;swapper/0 706 |
| cksum;entry_SYSCALL_64_fastpath;sys_write;vfs_write;__vfs_write;tty_write;n_tty_write;mutex_lock;_cond_resched;preempt_schedule_common;-;woken_wake_function;__wake_up_common;__wake_up;n_tty_read;tty_read;__vfs_read;vfs_read;sys_read;entry_SYSCALL_64_fastpath;;sshd 804 |
| supervise;retint_user;prepare_exit_to_usermode;exit_to_usermode_loop;schedule;-; 1101 |
| run;return_from_execve;sys_execve;do_execveat_common.isra.33;search_binary_handler;load_elf_binary;flush_old_exec;mmput;exit_mmap;free_pgtables;unlink_anon_vmas;__put_anon_vma;_cond_resched;preempt_schedule_common;-; 1122 |
| cksum;entry_SYSCALL_64_fastpath;sys_read;vfs_read;__vfs_read;generic_file_read_iter;__lock_page_killable;__wait_on_bit_lock;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;unlock_page;mpage_end_io;bio_endio;blk_update_request;blk_mq_end_request;__blk_mq_complete_request;readproctitle 1319 |
| run;int_ret_from_sys_call;syscall_return_slowpath;exit_to_usermode_loop;schedule;-; 1902 |
| cksum;entry_SYSCALL_64_fastpath;sys_read;vfs_read;__vfs_read;generic_file_read_iter;__lock_page_killable;__wait_on_bit_lock;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;unlock_page;mpage_end_io;bio_endio;blk_update_request;blk_mq_end_request;__blk_mq_complete_request;chown 1925 |
| supervise;entry_SYSCALL_64_fastpath;sys_rename;dput;__dentry_kill;iput;evict;ext4_evict_inode;truncate_inode_pages_final;truncate_inode_pages_range;wait_on_page_bit;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;end_page_writeback;ext4_finish_bio;ext4_end_bio;bio_endio;blk_update_request;blk_mq_end_request;cksum 2181 |
| cksum;entry_SYSCALL_64_fastpath;sys_open;do_sys_open;do_filp_open;path_openat;link_path_walk;walk_component;__lookup_hash;lookup_real;ext4_lookup;ext4_find_entry;__wait_on_buffer;out_of_line_wait_on_bit;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;wake_up_bit;unlock_buffer;__end_buffer_read_notouch;end_buffer_read_sync;end_bio_bh_io_sync;bio_endio;swapper/0 2599 |
| cksum;retint_user;prepare_exit_to_usermode;exit_to_usermode_loop;schedule;-; 2816 |
| supervise;ext4_rename2;ext4_rename;ext4_alloc_da_blocks;filemap_flush;__filemap_fdatawrite_range;do_writepages;ext4_writepages;ext4_map_blocks;ext4_ext_map_blocks;ext4_mb_new_blocks;ext4_mb_mark_diskspace_used;__ext4_journal_get_write_access;jbd2_journal_get_write_access;do_get_write_access;out_of_line_wait_on_bit;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;wake_up_bit;journal_end_buffer_io_sync;end_bio_bh_io_sync;bio_endio;blk_update_request;blk_mq_end_request;swapper/0 3393 |
| supervise;entry_SYSCALL_64_fastpath;sys_rename;dput;__dentry_kill;iput;evict;ext4_evict_inode;truncate_inode_pages_final;truncate_inode_pages_range;wait_on_page_bit;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;end_page_writeback;ext4_finish_bio;ext4_end_bio;bio_endio;blk_update_request;blk_mq_end_request;supervise 5398 |
| sshd;entry_SYSCALL_64_fastpath;sys_select;core_sys_select;do_select;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule;-;pollwake;__wake_up_common;__wake_up_sync_key;sock_def_readable;tcp_data_queue;tcp_rcv_established;tcp_v4_do_rcv;tcp_v4_rcv;ip_local_deliver_finish;ip_local_deliver;mkdir 6582 |
| cksum;entry_SYSCALL_64_fastpath;sys_read;vfs_read;__vfs_read;generic_file_read_iter;__lock_page_killable;__wait_on_bit_lock;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;unlock_page;mpage_end_io;bio_endio;blk_update_request;blk_mq_end_request;__blk_mq_complete_request;chmod 8310 |
| run;retint_user;prepare_exit_to_usermode;exit_to_usermode_loop;schedule;-; 8444 |
| supervise;entry_SYSCALL_64_fastpath;sys_rename;dput;__dentry_kill;iput;evict;ext4_evict_inode;truncate_inode_pages_final;truncate_inode_pages_range;wait_on_page_bit;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;end_page_writeback;ext4_finish_bio;ext4_end_bio;bio_endio;blk_update_request;blk_mq_end_request;readproctitle 9768 |
| supervise;entry_SYSCALL_64_fastpath;sys_rename;dput;__dentry_kill;iput;evict;ext4_evict_inode;truncate_inode_pages_final;truncate_inode_pages_range;wait_on_page_bit;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;end_page_writeback;ext4_finish_bio;ext4_end_bio;bio_endio;blk_update_request;blk_mq_end_request;run 9945 |
| cksum;entry_SYSCALL_64_fastpath;sys_read;vfs_read;__vfs_read;generic_file_read_iter;__lock_page_killable;__wait_on_bit_lock;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;unlock_page;mpage_end_io;bio_endio;blk_update_request;blk_mq_end_request;__blk_mq_complete_request;mkdir 11978 |
| cksum;entry_SYSCALL_64_fastpath;sys_open;do_sys_open;do_filp_open;path_openat;link_path_walk;walk_component;__lookup_hash;lookup_real;ext4_lookup;ext4_iget_normal;ext4_iget;__ext4_get_inode_loc;__wait_on_buffer;out_of_line_wait_on_bit;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;wake_up_bit;unlock_buffer;__end_buffer_read_notouch;end_buffer_read_sync;end_bio_bh_io_sync;bio_endio;swapper/0 12120 |
| cksum;link_path_walk;walk_component;__lookup_hash;lookup_real;ext4_lookup;ext4_iget_normal;ext4_iget;__ext4_get_inode_loc;submit_bh;submit_bh_wbc;submit_bio;generic_make_request;blk_sq_make_request;blk_mq_map_request;__blk_mq_alloc_request;blk_mq_get_tag;bt_get;__sched_text_start;schedule_timeout;schedule;-;autoremove_wake_function;__wake_up_common;__wake_up;bt_clear_tag;blk_mq_put_tag;__blk_mq_free_request;blk_mq_free_request;blk_mq_end_request;__blk_mq_complete_request;blk_mq_complete_request;swapper/0 23243 |
| cksum;entry_SYSCALL_64_fastpath;sys_open;do_sys_open;do_filp_open;path_openat;lookup_real;ext4_lookup;ext4_find_entry;__wait_on_buffer;out_of_line_wait_on_bit;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;wake_up_bit;unlock_buffer;__end_buffer_read_notouch;end_buffer_read_sync;end_bio_bh_io_sync;bio_endio;swapper/0 24767 |
| run;entry_SYSCALL_64_fastpath;sys_wait4;do_wait;schedule;-;child_wait_callback;__wake_up_common;__wake_up_sync_key;__wake_up_parent;do_notify_parent;do_exit;do_group_exit;sys_exit_group;entry_SYSCALL_64_fastpath;;chmod 33289 |
| run;entry_SYSCALL_64_fastpath;sys_wait4;do_wait;schedule;-;child_wait_callback;__wake_up_common;__wake_up_sync_key;__wake_up_parent;do_notify_parent;do_exit;do_group_exit;sys_exit_group;entry_SYSCALL_64_fastpath;;mkdir 34991 |
| cksum;entry_SYSCALL_64_fastpath;sys_read;vfs_read;__vfs_read;generic_file_read_iter;__lock_page_killable;__wait_on_bit_lock;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;unlock_page;mpage_end_io;bio_endio;blk_update_request;blk_mq_end_request;__blk_mq_complete_request;supervise 35746 |
| run;entry_SYSCALL_64_fastpath;sys_wait4;do_wait;schedule;-;child_wait_callback;__wake_up_common;__wake_up_sync_key;__wake_up_parent;do_notify_parent;do_exit;do_group_exit;sys_exit_group;entry_SYSCALL_64_fastpath;;chown 36942 |
| supervise;entry_SYSCALL_64_fastpath;sys_rename;dput;__dentry_kill;iput;evict;ext4_evict_inode;truncate_inode_pages_final;truncate_inode_pages_range;wait_on_page_bit;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;end_page_writeback;ext4_finish_bio;ext4_end_bio;bio_endio;blk_update_request;blk_mq_end_request;swapper/0 42993 |
| cksum;entry_SYSCALL_64_fastpath;sys_open;do_sys_open;do_filp_open;path_openat;lookup_real;ext4_lookup;ext4_iget_normal;ext4_iget;__ext4_get_inode_loc;__wait_on_buffer;out_of_line_wait_on_bit;__wait_on_bit;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;wake_up_bit;unlock_buffer;__end_buffer_read_notouch;end_buffer_read_sync;end_bio_bh_io_sync;bio_endio;swapper/0 53348 |
| sshd;entry_SYSCALL_64_fastpath;sys_select;core_sys_select;do_select;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule;-;pollwake;__wake_up_common;__wake_up;n_tty_receive_buf_common;n_tty_receive_buf2;flush_to_ldisc;process_one_work;worker_thread;kthread;ret_from_fork;kworker/u16:2 86256 |
| cksum;entry_SYSCALL_64_fastpath;sys_read;vfs_read;__vfs_read;generic_file_read_iter;__lock_page_killable;__wait_on_bit_lock;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;unlock_page;mpage_end_io;bio_endio;blk_update_request;blk_mq_end_request;__blk_mq_complete_request;run 109480 |
| ntpd;entry_SYSCALL_64_fastpath;sys_select;core_sys_select;do_select;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule;-;signal_wake_up_state;complete_signal;__send_signal;send_signal;do_send_sig_info;group_send_sig_info;kill_pid_info;it_real_fn;__hrtimer_run_queues;hrtimer_interrupt;cksum 999975 |
| ntpd;entry_SYSCALL_64_fastpath;sys_select;core_sys_select;do_select;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule;-;signal_wake_up_state;complete_signal;__send_signal;send_signal;do_send_sig_info;group_send_sig_info;kill_pid_info;it_real_fn;__hrtimer_run_queues;hrtimer_interrupt;swapper/0 999976 |
| supervise;entry_SYSCALL_64_fastpath;sys_poll;do_sys_poll;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule_hrtimeout_range_clock.part.23;schedule;-;hrtimer_wakeup;__hrtimer_run_queues;hrtimer_interrupt;xen_timer_interrupt;handle_irq_event_percpu;handle_percpu_irq;generic_handle_irq;evtchn_2l_handle_events;__xen_evtchn_do_upcall;xen_evtchn_do_upcall;chmod 1021082 |
| snmpd;entry_SYSCALL_64_fastpath;sys_select;core_sys_select;do_select;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule_hrtimeout_range_clock.part.23;schedule;-;hrtimer_wakeup;__hrtimer_run_queues;hrtimer_interrupt;xen_timer_interrupt;handle_irq_event_percpu;handle_percpu_irq;generic_handle_irq;evtchn_2l_handle_events;__xen_evtchn_do_upcall;xen_evtchn_do_upcall;swapper/0 1726275 |
| ntpd;entry_SYSCALL_64_fastpath;sys_select;core_sys_select;do_select;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule;-;signal_wake_up_state;complete_signal;__send_signal;send_signal;do_send_sig_info;group_send_sig_info;kill_pid_info;it_real_fn;__hrtimer_run_queues;hrtimer_interrupt;swapper/1 1999944 |
| supervise;entry_SYSCALL_64_fastpath;sys_poll;do_sys_poll;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule_hrtimeout_range_clock.part.23;schedule;-;hrtimer_wakeup;__hrtimer_run_queues;hrtimer_interrupt;xen_timer_interrupt;handle_irq_event_percpu;handle_percpu_irq;generic_handle_irq;evtchn_2l_handle_events;__xen_evtchn_do_upcall;xen_evtchn_do_upcall;cksum 2041945 |
| cksum;entry_SYSCALL_64_fastpath;sys_read;vfs_read;__vfs_read;generic_file_read_iter;__lock_page_killable;__wait_on_bit_lock;bit_wait_io;__sched_text_start;schedule_timeout;schedule;-;wake_bit_function;__wake_up_common;__wake_up;__wake_up_bit;unlock_page;mpage_end_io;bio_endio;blk_update_request;blk_mq_end_request;__blk_mq_complete_request;swapper/0 3720413 |
| vmstat;entry_SYSCALL_64_fastpath;sys_nanosleep;hrtimer_nanosleep;do_nanosleep;schedule;-;hrtimer_wakeup;__hrtimer_run_queues;hrtimer_interrupt;xen_timer_interrupt;handle_irq_event_percpu;handle_percpu_irq;generic_handle_irq;evtchn_2l_handle_events;__xen_evtchn_do_upcall;xen_evtchn_do_upcall;swapper/0 4000402 |
| tail;entry_SYSCALL_64_fastpath;sys_nanosleep;hrtimer_nanosleep;do_nanosleep;schedule;-;hrtimer_wakeup;__hrtimer_run_queues;hrtimer_interrupt;xen_timer_interrupt;handle_irq_event_percpu;handle_percpu_irq;generic_handle_irq;evtchn_2l_handle_events;__xen_evtchn_do_upcall;xen_evtchn_do_upcall;swapper/0 4000447 |
| readproctitle;entry_SYSCALL_64_fastpath;sys_read;vfs_read;__vfs_read;pipe_read;pipe_wait;schedule;-;autoremove_wake_function;__wake_up_common;__wake_up_sync_key;pipe_write;__vfs_write;vfs_write;sys_write;entry_SYSCALL_64_fastpath;;run 4149862 |
| offwaketime.py;entry_SYSCALL_64_fastpath;sys_select;core_sys_select;do_select;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule_hrtimeout_range_clock.part.23;schedule;-;hrtimer_wakeup;__hrtimer_run_queues;hrtimer_interrupt;xen_timer_interrupt;handle_irq_event_percpu;handle_percpu_irq;generic_handle_irq;evtchn_2l_handle_events;__xen_evtchn_do_upcall;xen_evtchn_do_upcall;swapper/1 5005058 |
| supervise;entry_SYSCALL_64_fastpath;sys_poll;do_sys_poll;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule_hrtimeout_range_clock.part.23;schedule;-;hrtimer_wakeup;__hrtimer_run_queues;hrtimer_interrupt;xen_timer_interrupt;handle_irq_event_percpu;handle_percpu_irq;generic_handle_irq;evtchn_2l_handle_events;__xen_evtchn_do_upcall;xen_evtchn_do_upcall;swapper/1 8168600 |
| sshd;entry_SYSCALL_64_fastpath;sys_select;core_sys_select;do_select;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule;-;pollwake;__wake_up_common;__wake_up;n_tty_receive_buf_common;n_tty_receive_buf2;flush_to_ldisc;process_one_work;worker_thread;kthread;ret_from_fork;kworker/u16:1 8821767 |
| supervise;entry_SYSCALL_64_fastpath;sys_poll;do_sys_poll;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule_hrtimeout_range_clock.part.23;schedule;-;hrtimer_wakeup;__hrtimer_run_queues;hrtimer_interrupt;xen_timer_interrupt;handle_irq_event_percpu;handle_percpu_irq;generic_handle_irq;evtchn_2l_handle_events;__xen_evtchn_do_upcall;xen_evtchn_do_upcall;run 9186846 |
| supervise;entry_SYSCALL_64_fastpath;sys_poll;do_sys_poll;poll_schedule_timeout;schedule_hrtimeout_range;schedule_hrtimeout_range_clock;schedule_hrtimeout_range_clock.part.23;schedule;-;hrtimer_wakeup;__hrtimer_run_queues;hrtimer_interrupt;xen_timer_interrupt;handle_irq_event_percpu;handle_percpu_irq;generic_handle_irq;evtchn_2l_handle_events;__xen_evtchn_do_upcall;xen_evtchn_do_upcall;swapper/0 20415299 |
| |
| This output format is suitable for feeding into the open source FlameGraph |
| software, which visualizes these. |
| |
| |
| USAGE message: |
| |
| # ./offwaketime -h |
| usage: offwaketime [-h] [-u] [-p PID] [-v] [-f] [duration] |
| |
| Summarize blocked time by kernel off-CPU stack + waker stack |
| |
| positional arguments: |
| duration duration of trace, in seconds |
| |
| optional arguments: |
| -h, --help show this help message and exit |
| -u, --useronly user threads only (no kernel threads) |
| -p PID, --pid PID trace this PID only |
| -v, --verbose show raw addresses |
| -f, --folded output folded format |
| |
| examples: |
| ./offwaketime # trace off-CPU + waker stack time until Ctrl-C |
| ./offwaketime 5 # trace for 5 seconds only |
| ./offwaketime -f 5 # 5 seconds, and output in folded format |
| ./offwaketime -u # don't include kernel threads (user only) |
| ./offwaketime -p 185 # trace fo PID 185 only |