tracing/histogram: Fix stacktrace histogram Documententation

Fix a small problem with the histogram specification in the
Documentation, and change the example to show output using a
stacktrace field rather than the global stacktrace.

Link: https://lkml.kernel.org/r/f75f807dd4998249e513515f703a2ff7407605f4.1676063532.git.zanussi@kernel.org

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Tom Zanussi 2023-02-10 15:33:06 -06:00 committed by Steven Rostedt (Google)
parent f5914b301a
commit d8f0ae3ebe

View File

@ -1993,82 +1993,106 @@ uninterruptible state::
A synthetic event that has a stacktrace field may use it as a key in A synthetic event that has a stacktrace field may use it as a key in
histogram:: histogram::
# echo 'hist:delta.buckets=100,stack.stacktrace:sort=delta' > events/synthetic/block_lat/trigger # echo 'hist:keys=delta.buckets=100,stack.stacktrace:sort=delta' > events/synthetic/block_lat/trigger
# cat events/synthetic/block_lat/hist # cat events/synthetic/block_lat/hist
# event histogram # event histogram
# #
# trigger info: hist:keys=delta.buckets=100,stacktrace:vals=hitcount:sort=delta.buckets=100:size=2048 [active] # trigger info: hist:keys=delta.buckets=100,stack.stacktrace:vals=hitcount:sort=delta.buckets=100:size=2048 [active]
# #
{ delta: ~ 0-99, stack.stacktrace __schedule+0xa19/0x1520
{ delta: ~ 0-99, stacktrace: schedule+0x6b/0x110
event_hist_trigger+0x464/0x480 io_schedule+0x46/0x80
event_triggers_call+0x52/0xe0 bit_wait_io+0x11/0x80
trace_event_buffer_commit+0x193/0x250 __wait_on_bit+0x4e/0x120
trace_event_raw_event_sched_switch+0xfc/0x150 out_of_line_wait_on_bit+0x8d/0xb0
__traceiter_sched_switch+0x41/0x60 __wait_on_buffer+0x33/0x40
__schedule+0x448/0x7b0 jbd2_journal_commit_transaction+0x155a/0x19b0
schedule_idle+0x26/0x40 kjournald2+0xab/0x270
cpu_startup_entry+0x19/0x20 kthread+0xfa/0x130
start_secondary+0xed/0xf0 ret_from_fork+0x29/0x50
secondary_startup_64_no_verify+0xe0/0xeb
} hitcount: 6
{ delta: ~ 0-99, stacktrace:
event_hist_trigger+0x464/0x480
event_triggers_call+0x52/0xe0
trace_event_buffer_commit+0x193/0x250
trace_event_raw_event_sched_switch+0xfc/0x150
__traceiter_sched_switch+0x41/0x60
__schedule+0x448/0x7b0
schedule_idle+0x26/0x40
cpu_startup_entry+0x19/0x20
__pfx_kernel_init+0x0/0x10
arch_call_rest_init+0xa/0x24
start_kernel+0x964/0x98d
secondary_startup_64_no_verify+0xe0/0xeb
} hitcount: 3
{ delta: ~ 0-99, stacktrace:
event_hist_trigger+0x464/0x480
event_triggers_call+0x52/0xe0
trace_event_buffer_commit+0x193/0x250
trace_event_raw_event_sched_switch+0xfc/0x150
__traceiter_sched_switch+0x41/0x60
__schedule+0x448/0x7b0
schedule+0x5a/0xb0
worker_thread+0xaf/0x380
kthread+0xe9/0x110
ret_from_fork+0x2c/0x50
} hitcount: 1 } hitcount: 1
{ delta: ~ 100-199, stacktrace: { delta: ~ 0-99, stack.stacktrace __schedule+0xa19/0x1520
event_hist_trigger+0x464/0x480 schedule+0x6b/0x110
event_triggers_call+0x52/0xe0 io_schedule+0x46/0x80
trace_event_buffer_commit+0x193/0x250 rq_qos_wait+0xd0/0x170
trace_event_raw_event_sched_switch+0xfc/0x150 wbt_wait+0x9e/0xf0
__traceiter_sched_switch+0x41/0x60 __rq_qos_throttle+0x25/0x40
__schedule+0x448/0x7b0 blk_mq_submit_bio+0x2c3/0x5b0
schedule_idle+0x26/0x40 __submit_bio+0xff/0x190
cpu_startup_entry+0x19/0x20 submit_bio_noacct_nocheck+0x25b/0x2b0
start_secondary+0xed/0xf0 submit_bio_noacct+0x20b/0x600
secondary_startup_64_no_verify+0xe0/0xeb submit_bio+0x28/0x90
} hitcount: 15 ext4_bio_write_page+0x1e0/0x8c0
[..] mpage_submit_page+0x60/0x80
{ delta: ~ 8500-8599, stacktrace: mpage_process_page_bufs+0x16c/0x180
event_hist_trigger+0x464/0x480 mpage_prepare_extent_to_map+0x23f/0x530
event_triggers_call+0x52/0xe0 } hitcount: 1
trace_event_buffer_commit+0x193/0x250 { delta: ~ 0-99, stack.stacktrace __schedule+0xa19/0x1520
trace_event_raw_event_sched_switch+0xfc/0x150 schedule+0x6b/0x110
__traceiter_sched_switch+0x41/0x60 schedule_hrtimeout_range_clock+0x97/0x110
__schedule+0x448/0x7b0 schedule_hrtimeout_range+0x13/0x20
schedule_idle+0x26/0x40 usleep_range_state+0x65/0x90
cpu_startup_entry+0x19/0x20 __intel_wait_for_register+0x1c1/0x230 [i915]
start_secondary+0xed/0xf0 intel_psr_wait_for_idle_locked+0x171/0x2a0 [i915]
secondary_startup_64_no_verify+0xe0/0xeb intel_pipe_update_start+0x169/0x360 [i915]
intel_update_crtc+0x112/0x490 [i915]
skl_commit_modeset_enables+0x199/0x600 [i915]
intel_atomic_commit_tail+0x7c4/0x1080 [i915]
intel_atomic_commit_work+0x12/0x20 [i915]
process_one_work+0x21c/0x3f0
worker_thread+0x50/0x3e0
kthread+0xfa/0x130
} hitcount: 3
{ delta: ~ 0-99, stack.stacktrace __schedule+0xa19/0x1520
schedule+0x6b/0x110
schedule_timeout+0x11e/0x160
__wait_for_common+0x8f/0x190
wait_for_completion+0x24/0x30
__flush_work.isra.0+0x1cc/0x360
flush_work+0xe/0x20
drm_mode_rmfb+0x18b/0x1d0 [drm]
drm_mode_rmfb_ioctl+0x10/0x20 [drm]
drm_ioctl_kernel+0xb8/0x150 [drm]
drm_ioctl+0x243/0x560 [drm]
__x64_sys_ioctl+0x92/0xd0
do_syscall_64+0x59/0x90
entry_SYSCALL_64_after_hwframe+0x72/0xdc
} hitcount: 1
{ delta: ~ 0-99, stack.stacktrace __schedule+0xa19/0x1520
schedule+0x6b/0x110
schedule_timeout+0x87/0x160
__wait_for_common+0x8f/0x190
wait_for_completion_timeout+0x1d/0x30
drm_atomic_helper_wait_for_flip_done+0x57/0x90 [drm_kms_helper]
intel_atomic_commit_tail+0x8ce/0x1080 [i915]
intel_atomic_commit_work+0x12/0x20 [i915]
process_one_work+0x21c/0x3f0
worker_thread+0x50/0x3e0
kthread+0xfa/0x130
ret_from_fork+0x29/0x50
} hitcount: 1
{ delta: ~ 100-199, stack.stacktrace __schedule+0xa19/0x1520
schedule+0x6b/0x110
schedule_hrtimeout_range_clock+0x97/0x110
schedule_hrtimeout_range+0x13/0x20
usleep_range_state+0x65/0x90
pci_set_low_power_state+0x17f/0x1f0
pci_set_power_state+0x49/0x250
pci_finish_runtime_suspend+0x4a/0x90
pci_pm_runtime_suspend+0xcb/0x1b0
__rpm_callback+0x48/0x120
rpm_callback+0x67/0x70
rpm_suspend+0x167/0x780
rpm_idle+0x25a/0x380
pm_runtime_work+0x93/0xc0
process_one_work+0x21c/0x3f0
} hitcount: 1 } hitcount: 1
Totals: Totals:
Hits: 89 Hits: 10
Entries: 11 Entries: 7
Dropped: 0 Dropped: 0
2.2.3 Hist trigger 'handlers' and 'actions' 2.2.3 Hist trigger 'handlers' and 'actions'
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